Buy the RIO Gold ($99.99) if you fish a mix of dries, nymphs, and light streamers and want one line that never feels wrong for the water in front of you. Buy the Cortland 444 Peach ($69.95) if you want a second line, a backup spool, or a line built for a medium or slow-action rod without paying for coating chemistry you will not use. The Scientific Anglers Amplitude Smooth MPX ($99.95) is the pick for small streams and pocket water under 40 feet, and the Airflo Superflo Max Ridge 2.0 Super Trout ($129.99) is the one built for open water, long mends, and cold-weather fishing.

The variable that separates these five lines is how much mass sits in the head and where. A line built heavier than the industry standard loads a rod faster at short range; a line with a long head carries more weight in the air for distance and mending. Everything else, coating chemistry, core material, texture, changes how that mass behaves once it is moving.

The picks at a glance

Pick Best for Price (September 2026) Distinguishing spec
RIO Gold All-around, one line for everything $99.99 47 ft head, standard weight, SlickCast coating
SA Amplitude Smooth MPX Small streams, pocket water under 40 ft $99.95 36 ft head, half-size heavy (150 gr), braided core
Airflo Superflo Max Ridge 2.0 Super Trout Open water, long mends, cold weather $129.99 70.7 ft head, PVC-free polyurethane, Ridge 2.0 texture
Orvis PRO Trout Smooth Mending at range $98 50 ft head, AST Plus coating, 3 marked color sections
Cortland 444 Peach Value, backup spool, slower rods $69.95 32 ft head, exactly 140 gr on the AFTMA standard

How to choose a 5-weight fly line

Grain weight vs the AFFTA standard and why premium lines run heavy

A 5-weight floating line is measured against an industry reference of about 140 grains in the first 30 feet of the head. Airflo lists that exact number as the "AFTMA weight (30 ft)" on its Super Trout spec sheet, even though that line's total head weighs 299 grains over 70.7 feet. That gap is the story with a long-belly taper: measured against the 30-foot checkpoint alone, the Airflo reads right on spec, but most of its mass sits beyond that point, out where it carries line and mends at distance.

Not every line sits at 140 grains. Scientific Anglers builds the Amplitude Smooth MPX at 150 grains in the first 30 feet, about 10 over standard, and calls the taper "half-size heavy": enough extra mass up front to load a fast rod inside 40 feet without a long false-casting stroke. Cortland's 444 Peach comes in exactly on the 140-grain mark, the number it has carried since 1962. RIO markets the Gold as "standard weight, standard power," which puts it with Cortland rather than SA, though RIO does not publish a grain table for the Gold.

Head length and front taper

Head length decides how much line you carry in the air before it turns over, and it more than doubles across these five lines. Cortland's 444 Peach carries the shortest head at 32 feet, the classic taper the line has used since 1962. Scientific Anglers' Amplitude Smooth MPX runs 36 feet, RIO's Gold 47 feet with a 5-foot-6-inch front taper, and Orvis's PRO Trout Smooth 50 feet with what Orvis calls a gentle front taper into "a powerful belly." Airflo's Super Trout is the outlier at 70.7 feet of total head on a 120-foot line, a taper Airflo's own copy says "started life as a long belly tournament line" before becoming, in the company's words, an in-house favorite for most trout situations.

A short head loads with less line out of the tip, which matters on brushy freestone water where a long back cast finds rhododendron. A long head carries more weight in the air at distance and more line to work with when a fish takes 40 feet out and the current bows the belly into a mend.

Coating chemistry: PVC vs polyurethane in the cold

RIO, Scientific Anglers, and Orvis all start from a PVC base. RIO coats the Gold with SlickCast and adds MaxFloat Tip Technology to the first section. Scientific Anglers and Orvis both use a treatment called AST Plus, described in nearly identical language on both companies' pages: a slickness additive that migrates to the surface, sheds dirt and oil, and keeps working as the coating wears.

Airflo builds the Super Trout from a different base. Airflo's own site says the company has sold PVC-free lines since 1984, and describes its polyurethane coating as more abrasion-resistant and unlikely to crack under UV exposure or extreme temperatures. The difference shows up below about 45 degrees: PVC coatings stiffen and coil on the casting stroke, while a polyurethane coating stays supple. In July, both chemistries float and shoot about the same.

Core material and stretch

A line's core sets how much it stretches under a hookset or a hard mend. Three of the five lines here publish a core spec: Scientific Anglers' Amplitude Smooth MPX uses a braided multifilament core, Airflo's Super Trout a 20-pound braided core, and Cortland's 444 Peach a braided nylon multifilament core. RIO and Orvis do not list core material on the Gold's or the PRO Trout Smooth's product pages.

Braided cores stretch less than monofilament, so a strike travels to the rod hand faster and a hookset moves the hook point instead of taking up slack first. The tradeoff is less shock absorption on a hard take, which matters more on light tippet than on anything a 5-weight throws. All three published cores here are the low-stretch braided type, now the standard at this price point.

Textured vs smooth surfaces

Airflo's Super Trout is the one textured line in this group. Airflo calls the technology Ridge 2.0, a dual-polymer design that blends two hardness levels into a raised surface pattern meant to cut friction through the guides and add shooting distance. Scientific Anglers sells the same MPX taper in a textured version too, the Amplitude Textured MPX at $129.95, a different product from the Amplitude Smooth MPX reviewed here.

The other four lines rely on a smooth coating and a slickness additive instead of surface texture. A smooth coating runs quieter through the guides and picks up less streamside grit. Texture earns its keep at longer distances and on lines cleaned less often than they should be.

RIO Gold: the all-around standard

Specs:

  • Taper: WF5F, marketed as standard weight and standard power
  • Head length: 47 ft, with a 5-foot 6-inch front taper
  • Coating: SlickCast slickness technology with MaxFloat Tip on the first section
  • Total length: 80 ft
  • Price: $99.99 at farbank.com, September 2026

RIO now sells the Gold taper across three tiers, Avid, Premier, and Elite; the product listed simply as "RIO Gold" in RIO's own navigation is the Premier tier, the current naming as of September 2026.

The 47-foot head and long back taper are what earn the Gold its reputation as the line that does the least wrong. RIO's copy describes it as built to load a rod at close range while giving total line control and stability at distance, and the standard weight rating means predictable loading on rods from medium to fast action, without the front-end punch of a half-size-heavy taper. The 5-foot-6-inch front taper lays a size 16 dry down without a splat and still turns over a size 10 stonefly nymph under an indicator. The limit is what RIO does not publish: no core material appears on the Gold's product page, so there is no way to compare its stretch against the MPX or the 444 Peach from RIO's own spec sheet.

Buy if: You want one 5-weight line that handles dries, nymphs, and light streamers without a weak spot.

Skip if: You fish almost exclusively inside 30 feet on small water, where the MPX's short, front-loaded taper loads faster.

Where to buy: RIO Gold WF5F

Scientific Anglers Amplitude Smooth MPX: built for close water

Specs:

  • Taper: WF5F, built half-size heavy
  • Head length: 36.0 ft
  • Head weight: 175 gr; grain weight in the first 30 ft: 150 gr
  • Core: braided multifilament
  • Coating: AST Plus slickness additive
  • Total length: 90 ft
  • Price: $99.95 at scientificanglers.com, September 2026

MPX began as SA's GPX taper redesigned with more mass toward the front of the head, an emphasis SA's page describes as keeping the benefits of the GPX "with an added emphasis on presentation." Built half-size heavy at 150 grains against the 140-grain standard, the head loads a fast-action rod inside 40 feet with less false casting than a standard-weight line needs.

The 36-foot head is the shortest of the four premium lines here, ahead of only Cortland's 32-foot 444 Peach. That is an advantage on brushy small streams and a limit on open water: past about 50 feet the head runs out and the running line does work it is not built for. The braided multifilament core keeps stretch low, so a strike on a size 16 Parachute Adams registers in the rod hand. The half-size-heavy taper is also the thing to watch on a medium or slow-action rod already built to load easily: pairing it with a softer rod can put more line speed into the stroke earlier than the caster expects.

Buy if: You fish small streams or pocket water under 40 feet and want a fast-loading, half-size-heavy taper.

Skip if: You cast a medium or slow-action rod, or you fish open water past 50 feet regularly.

Where to buy: Scientific Anglers Amplitude MPX

Airflo Superflo Max Ridge 2.0 Super Trout: the long-belly, cold-weather line

Specs:

  • Taper: WF5F, Ridge 2.0 textured surface
  • Head length: 70.7 ft total head
  • Head weight: 299 gr; AFTMA weight in the first 30 ft: 140 gr
  • Core: 20 lb braided
  • Total length: 120 ft
  • Coating: PVC-free polyurethane
  • Price: $129.99 at mayflyoutdoors.com (Airflo USA), September 2026; WF5F was listed sold out at the time of this research, WF7F in stock

Airflo's own copy says the Super Trout "started life as a long belly tournament line" before becoming an in-house favorite for most trout situations. The 70.7-foot total head is more than double RIO Gold's, and most of its 299 grains sit beyond the 30-foot mark the AFTMA standard measures. That is the line for bigger smallmouth pools, or any water where the average cast runs past 50 feet and a long upstream mend has to move a lot of line at once.

The Ridge 2.0 surface and polyurethane base are the other reasons to own this line. Airflo has built PVC-free lines since 1984, and its current marketing describes the coating as more abrasion-resistant and unlikely to crack under UV exposure or extreme temperatures, a real difference below about 45 degrees, when PVC coatings stiffen and coil on the cast. The tradeoff is the head length itself: 70.7 feet needs more line speed and a longer stroke to fully extend than the 36-to-50-foot heads on the other four lines here. The WF5F size was also listed as sold out on Airflo USA's own site at the time of this research, with only the WF7F in stock, so check current availability before ordering.

Buy if: You fish open, bigger water and want a line built to shoot and mend at 50 feet and beyond, especially in cold weather.

Skip if: You are still building casting stroke length, or you fish tight, brushy water where a 70-foot head never gets the chance to extend.

Orvis PRO Trout Smooth: the mending line

Specs:

  • Taper: WF, sold in 3wt through 8wt, smooth compound taper
  • Head length: 50 ft, a gentle front taper into a longer belly
  • Coating: AST Plus slickness treatment
  • Core: not published on the product page
  • Total length: 90 ft, with marked color sections at 8 ft and 30 ft
  • Price: $98 at orvis.com, September 2026

Orvis's PRO Trout Smooth sits between RIO Gold and Airflo's Super Trout on head length, at 50 feet against RIO's 47 and Airflo's 70.7. Orvis describes the taper as a gentle front taper into a powerful belly for easy casting and delicate presentation, with a longer rear taper built for better line control and on-water mending. At $98 it undercuts both the RIO Gold and the SA MPX slightly, with a similar all-around role.

The coating name is the surprise: Orvis's AST Plus treatment carries the identical name Scientific Anglers uses on the Amplitude Smooth MPX, described in nearly the same language on both companies' pages, down to the claim that it continuously migrates to the surface and sheds dirt. That does not mean it is the same formula, but it points to a shared coating supplier behind more of the mid-tier market than the brand names suggest. What Orvis does not publish is worth naming: no grain weight table and no core material appear on the page, so there is no way to check this line against the AFTMA reference the way SA's and Airflo's pages allow. The 90-foot total length is split into marked color sections at 8 feet and 30 feet, which helps a caster judge distance but also puts a visible color break inside the zone where a spooky trout is looking up.

Buy if: You want a line built specifically for mending at range and a color-marked head for judging distance.

Skip if: You want to verify grain weight against the AFTMA standard before buying; Orvis does not publish it.

Cortland 444 Peach: the value pick

Specs:

  • Taper: WF5F, classic all-purpose taper introduced in 1962
  • Head length: 32 ft
  • Grain weight: 140 gr, exactly on the AFTMA standard
  • Core: braided nylon multifilament
  • Total length: 90 ft, with 58 ft of running line
  • Price: $69.95 at cortlandline.com, September 2026

The 444 Peach has carried the same name and the same 32-foot head since Cortland introduced it in 1962, and it is the only line here priced under $70. The WF5F grain weight lands exactly on the 140-grain AFTMA reference, so it loads a rod the way the standard says a 5-weight line should, without RIO's or SA's added front-end mass.

Cortland builds the 444 Peach on a braided nylon multifilament core, the same low-stretch construction SA and Airflo use on their premium lines, at less than three-quarters the price of either. The 32-foot head, four feet shorter than the MPX, makes it the fastest-loading line here at short range and the one that runs out of head soonest past 40 feet. What it does not offer is any of the coating chemistry claims the other four make: Cortland's page lists a high-floating coating without naming a slickness additive, a PVC-free formula, or a friction-reducing texture. For a line that costs $30 to $60 less than the others, that is the tradeoff, not a defect.

Buy if: You want a second line or a backup spool without paying premium prices, or you fish a slower rod that does not need extra front-end weight.

Skip if: You want a specific cold-weather or texture claim verified by the manufacturer; Cortland does not make one for this line.

Which one to buy

Start with where you fish, not the price. If your casts average under 40 feet on small, brushy water, the half-size-heavy Amplitude Smooth MPX loads faster than anything else here and its 36-foot head never asks for more room than the water gives it. If you fish open pools on the Susquehanna or the Shenandoah, or through November and December on a tailwater, the Airflo Super Trout's 70.7-foot head and PVC-free coating are built for that, though check current stock in your line weight first.

For everything between those extremes, which is most Mid-Atlantic trout fishing most of the year, the RIO Gold and the Orvis PRO Trout Smooth do nearly the same job at nearly the same price. The Gold's shorter head and standard weight rating make it marginally easier to load on a wider range of rod actions; the Orvis line's longer rear taper is built more specifically around mending at range.

For the typical reader of this site, a Mid-Atlantic trout angler who fishes 20 to 40 days a year across freestone and limestone water, the pick is the RIO Gold at $99.99: the line least likely to be the wrong choice for whatever the day brings. Anyone who wants a spare spool, or fishes a medium-action rod that does not need SA's extra front-end weight, should put that money into the Cortland 444 Peach instead.

Questions people ask

Do I need a heavier line to load a fast-action 5-weight rod?

Not necessarily. A standard-weight line like the RIO Gold or the Cortland 444 Peach loads a fast rod correctly at the distance the AFTMA standard was built around. A half-size-heavy line like the Amplitude MPX loads that same rod faster and closer, which helps more on small water under 40 feet than anywhere else.

What is the difference between a half-size-heavy taper and a standard-weight taper?

A standard WF5F carries about 140 grains in the first 30 feet. A half-size-heavy taper like the Amplitude Smooth MPX carries about 150. The extra grains load the rod tip sooner in the casting stroke, which shows up as easier casting at short range and less precision at long range.

Does fly line coating chemistry matter if I only fish in warm months?

Less than in winter. PVC and polyurethane coatings float and shoot at similar rates above about 50 degrees. The difference shows up below 45 degrees, when PVC lines stiffen and develop memory coils that a polyurethane line like Airflo's Super Trout does not.

How often should a 5-weight floating line be replaced?

There is no fixed number of casts. Watch for cracking in the coating, a line that no longer floats after cleaning, or a core gone soft and stretchy under normal hooksets. A line fished 20 to 40 days a year and cleaned a few times a season typically holds up for several years before any of those show up.

Updated September 15, 2026.