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We have long been fans of the Gamma line of jackets from Arc'teryx, as they are durable, dependable, weather-resistant, and comfortable. This heavier jacket is lined with a fleece backing, making it a good option for colder activities like winter hiking and ski touring. With a clean look and a trim fit, it is also versatile enough to wear in casual settings. While the Gamma MX is one of the top performers in weather protection, it does not do as well during intense activity — the fleece liner prevents it from being as breathable as its lighter-weight cousins in the Gamma line. We recommend the MX for those living in colder climates or who favor additional wind protection, while other versions from the same line suit a more active profile and milder weather.
REASONS TO BUY
Athletic fit
Intelligent pocket placements
Dependable weather protection
REASONS TO AVOID
Less-than-ideal breathability
Less versatile
Which Gamma Model is Right for You?
Arc'teryx has three different softshells in the Gamma line. This model is the heaviest out of the three, favoring weather protection as its most dominant feature. The midweight option, the Gamma Hoody, blends weather resistance and breathability into a more balanced package. The lightest option, the Gamma Lightweight Hoody, is a great option when breathability is most important, but it comes with a cost: reduced weather protection.
Wee Burly (56% nylon, 34% polyester, 10% elastane) with Arc'teryx Nu DWR treatment
Proflex: recycled polyester knit face 3L with PU membrane and recycled polyester backer
Lightweight Matrix single weave with 2-way stretch (85% nylon 6, 15% elastane) with DWR
92% polyester, 8% spandex
Insulated
Yes
No
No
No
Yes
Hood
Yes, helmet compatible StormHood
Yes, helmet compatible, adjustable StormHood
Yes, under helmet with rear hood adjustment
Yes, under helmet with Lycra binding
No
Unique Features
Well-tailored for technial use, highly effective over-helmet hood, easy-access hand pockets
Athletic slim fit, large over-helmet hood, all-arounder performance
Breathable water resistance, relaxed fit, adjustability
Chest pockets become ventilation, packs inside chest pocket
Top-tier heat retention
Layering Capabilities
Can be layered over or under other layers
Best worn under other layers
Can be layered over or under other layers
Can be layered over or under other layers
Can be layered over or under other layers
Adjustable Cuffs (Material)
No (fixed elastic cuffs)
No (stretch cuffs)
Yes (Velcro cuffs)
No (fixed elastic cuffs)
Yes (Velcro cuffs)
Available Sizes
XS - 2XL
XS - 2XL
S - 2XL
XS - 2XL
XS - 5XL
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Our Analysis and Test Results
The Arc'teryx Gamma MX Hoody is a trim, fitted softshell jacket that offers excellent weather protection and warmth. It has features that are well thought out and user-friendly and is stylish enough to wear both in the mountains and out to dinner. This jacket performs best during lower exertion activities in cold weather, where breathability won't be an essential part of your layering.
Performance Comparison
Hiking on a cold and breezy fall day is a great place for the Gamma MX to shine.
Credit: Ryan huetter
Weather Protection
The “MX” in Gamma MX stands for mixed weather, and this is a jacket that does better than most in these challenging conditions. The jacket uses a proven stretch fabric Arc'teryx has long used in their Gamma line, a fabric that effectively blocks wind, snow, and light rain. This stretch-woven Fortius 2.0 fabric keeps the elements at bay, beading water off in light precipitation thanks to its DWR treatment. However, with prolonged exposure to moisture, like all softshell jackets, this one will wet through and at a faster rate than shells with a heavier coating.
In a light drizzle water beads right off, though in a prolonged shower the fabric begins to wet out along the shoulders and back.
Credit: Ryan Huetter
With a large helmet-compatible hood, the Gamma MX Hoody is capable of sealing around the face, and the high zipper closes securely around the chin with a comfortable brushed fleece backing. The wrist cuffs utilize a fitted gasket that is somewhat stretchy. This fit our tester's wrists quite comfortably and sealed effectively, though it proved tough to fit these cuffs over even lightweight gloves.
Breathability
The Gamma MX uses a proprietary fabric comprised of polyester, nylon, and elastane called Fortius 2.0. It has been one of our lead reviewer's favorites for traveling in colder temperatures during moderately aerobic activities like ice climbing and ski touring. The fabric is air permeable and effectively passes moisture through to keep the body cool and dry during activity. However, on the MX, the fleece-backed lining does inhibit this ventilation to some extent. We found that during extended activity, we were noticeably wetter between the inner lining of our softshell and the exterior of our fleece mid-layer than when we wore a softshell without a lining. Unlined jackets do a better job of allowing moisture to pass through without wetting out interior materials.
This jacket does breathe, but given the fleece backing it is better suited for lower-output activities like hiking, climbing, or backcountry skiing.
Credit: Henry Huetter
Mobility
Arc'teryx is known for well-fitting garments that feel tailored in all of the right places. The Gamma MX is no exception. It is a trim, athletic fit, despite descriptions from Arc'teryx claiming a regular fit. They also describe this jacket as being hip-length. Yet our testers found that it barely covered their waists. Given that the arm length and torso are also close-fitting (to the point of being snug when layered over a mid-layer), consider sizing up for this jacket.
The stretch-woven panels of the Gamma MX move well with the body. Despite having no means to secure the cuffs other than a fitted gasket, we did not experience any drop in the cuff while reaching overhead. The hem, however, rises considerably. For us, this exposed baselayers and skin and pulled the jacket from under a harness while climbing.
As you can see, this product does a pretty good job of staying on Phil's wrist even without velcro. What you can't see is that it pulled up a little at the waist.
Credit: Jeremy Bauman
Weight
The Gamma MX jacket has a verified weight of 21 ounces for a medium. It is, however, a much more capable jacket than others that weigh the same or more. It's also bulkier, but the soft and flexible fabric expertly masks this. That being said, when stuffed in a pack, it takes up much more room than a lighter-weight model, so be prepared.
Versatility
Like the rest of the Gamma models we have worn, the Gamma MX has well-thought-out features that climbers and skiers can appreciate. The full-sized hood accommodates both ski and climbing helmets and has a three-way cinch system with hidden cord locks to ensure a tight seal around the face. The collar is lined with soft fleece, and a rubber gasket backs the zipper. There are two handwarmer pockets, as well as two Napolean-style chest pockets that are easy to access if you are wearing a harness or a pack.
The three-way closure on the hood is easy to operate, even with gloved hands.
Credit: Henry Huetter
The left shoulder features a small zippered pocket that we like for stashing a GU gel pack or our ski pass. There are no interior pockets. While the wrist closures are not adjustable, they do form a pretty good seal around the wrist. Those wishing to wear gloves, however, likely will prefer a jacket with adjustable cuffs. That said, the sleeves are fitted enough to accommodate gloves going over the top as well.
The fitted cuffs offer the best seal of any of the jackets that employ them, though we prefer velcro wrist closures for more usefulness with gloves.
Credit: Ryan huetter
Style-wise, we are continually impressed with the Gamma MX. It is clean-cut, has a tailored, athletic fit, and is equally fashionable on the cliffs or at the coffee shop. It is available in attractive colors that are not out of place in an urban setting.
Should You Buy the Arc'Teryx Gamma MX?
This is one of the most expensive jackets we tested, though it performs very well. For such a pricey option, we'd love to see more versatility, but in cooler weather, this is very dependable and likely to become a winter staple on less aggressively active days. If price isn't a consideration and you're seeking a jacket for chilly conditions, this is worthy of being in your closet.
What Other Jackets Should You Consider?
The Patagonia R2 Techface is an excellent option in the warm softshell category, with better breathability and weather resistance than the MX, though it's not as athletic of a cut. If you're seeking a more versatile option, the Arc'Teryx Gamma Hoody is an excellent all-arounder.
