I wore this jacket once and ended up returning it after skiing at Schweitzer on a spring-like day with dense, misty fog. By noon the jacket was soaking wet. I got it for spring skiing conditions, but realized that I would never use it for Pacific Northwest skiing where the snow is always wet. Otherwise, if I was still living in Utah I would have kept it for those drier conditions. Other than that, the fit was great and I loved the way I could move freely. The helmet-compatible hood, which I didn't initially think was a big deal, I ended up using towards the end of the day when it got a bit chillier. I ended up getting a Gore-Tex shell instead which I used up at Whistler and was perfect. Bottom line is, for wet climates it's probably not as functional, but for drier, colder places it's probably perfect.

For backcountry skiing, alpine climbing, and also walk in the town, this is my must-have jacket now, and I can't survive without it anymore! Great stretchy material doesn't bother me at all when I do any hard move on rock, and I love this hood which fit over a helmet when I get cold while I'm belaying, and it doesn't disturb head movement either, like hard shell hoody does. Only thing sometimes bothers me is the cuff. Elastic is a bit too tight when I want to roll up for warm temperature.

This is a great jacket! The fit is very close to the sizing as advertised, the longer cut fits well and keeps you warm, and the hood is actually functional (you have peripheral vision, can wear it with a helmet, etc.) It is not meant for a downpour - it will soak though and although you'll be warm, you'll be damp. It's very rainy where I am so I now use a rain shell on top on really wet days but it's great in snow or light rain. Also love the colour (got the pink).

I LOVE this jacket. It breathes well (which is a big plus for tele skiing), provides nice coverage in the back (so the jacket doesn't ride up when wearing a pack) and is quite stylie. Those Arcteryx Canadians sure knew what they were doing when they designed this jacket.

I went to the Swiss Alps over the Christmas break and I have to say this was just what I needed. I had to do a good bit of hiking and it was light enough that it didn't weigh me down. At the same time it kept me warm in 15 degree (fahrenheit) temperatures. I wore a base layer and a long sleeved cotton shirt underneath. It's very sleek and not bulky which came in handy when I wanted to take it off and wrap it around my waist. The pockets really warmed up my hands, which were cold even with gloves on!

I received this jacket as a gift this Christmas and I have used it nearly every day since for running (I live in the NE and like to run outside year-round). Even with the Artic air mass that just moved through my area and the sub-zero windchills, I was able to run comfortably with only light base layer and this jacket.
At first I thought the hood was a bit floppy, but I certainly appreciated it last week I was running in the rain and snow. The hood's design is amazing - the cinches keep the hood in place even with lots of movement, and the mini-bill keeps the weather off your face.
Unbelievable water and wind resistance, superb breathability and so sleek!

I’m a runner and climber, I run on the trail year-round and this is the jacket I wear during winter months. At 25F, I stay very warm with this jacket and just a Rho top. It blocks out most of the wind and yet it’s very breathable. The soft fleece lining is warm but not too hot. The hood protects your head and ears from the freezing wind. The shell is very water resistant, it will keep you dry in the snow but for heavy downpours, I’d wear the Alpha SV which is super waterproof and another one of my favorites. Arcteryx makes the most stylish and sleek looking performance clothes.

I received this jacket yesterday. I feel confident in saying that this jacket has definitely met my expectations even though I have only run in it twice. I am a long-distance runner and have tried MANY jackets in the windy, wet and cold Canadian winters. I have only one other jacket (Mountain Hardwear Gorestopper) that I feel comfortable running in during winter, but it has no hood. Yesterday the weather was calm and approximately 32F. I ran 10 miles wearing only a Patagonia base layer and I felt so comfortable wearing my Gamma MX Hoody. Today I ran in much different conditions 20mph winds, raining heavily and temperature of approximately 35F. I used the hood which was not bulky and did not annoy me. Despite the terrible weather conditions, I felt comfortable running 8 miles. I run marathons so I put in a lot of miles training. I am very particular about what I wear during my training runs and the fact that I am pleased with the Gamma MX Hoody says a lot for it!! So, can I say that I already love this jacket.....yes!!

Since it's the middle of summer, I haven't had a chance to test-drive the jacket, so I can only comment on the fit and the comparison with the Arc'teryx Gamma SV. That said, I already know I'm going to love it: It fits like a glove and looks even better than the Gamma SV (which my friends already tell me looks great). The fit is pretty close-to-the-body but not tight (and just FYI, I'm 5'3" and 130 lbs and wear a small); I could probably fit a baselayer but not a fleece underneath. While there's enough fabric under the arms to allow you to raise your arms without the jacket moving, it doesn't feel bulky at all (in contrast to the Gamma SV, whose fabric bunches up under my arms).
The hood is well-constructed, with a stiffened bill to keep rain off your face and a drawcord to help shrink it down if you're not wearing a helmet underneath. Compared with the Gamma SV, the Gamma MX has thinner fabric and is cut longer, falling below the hip; it also seems to fit a bit more closely, perhaps because the Gamma SV might be meant to accommodate more layers. I expect that I'll wear the jacket for anything from highly aerobic sports like X-C skiing when the temperatures are above 25F and I can't wear a long-sleeved baselayer under my Gamma SV, to autumn strolls around town. Between this jacket and the Gamma SV, I'm covered for almost anything the weather can throw at me from September to April!

Living in MN means windchills enough to make the real temperature feel below zero. I would have to say this jacket though gets you moving without fear. I just wear a thin long underwear layer or two underneath and I'm out the door. comfortably set to move without any bulk. the hood is fantastic too to keep warmth and wind out. overall, I'm ecstatic. without this jacket, I'd be miserable and stuck inside. I'm hoping to look for pants that are as comfortable to move in as this jacket!!

Pit zips and a way to stow the hood. I like the jacket, but I'm going to have to sew on a strap to keep the hood rolled. It comes unrolled easily, and if you are running or riding it's annoying to have the hood flopping around in back to tangle with packs and such.

Love the fit, feel and freedom of movement. The hood fitting over my helmet is a definite plus. But I'm disappointed at the lack of obvious, useful details, and at this price point, the features should be there.

I love the soft hand-feel of this jacket. It is really light and has a nice soft lining. What I was impressed with, that you can't tell from the photos of this jacket, are the drawcords. They are placed so that you can snug the hood to a perfect fit on your head and even adjust for height. I bought it in Aloe Green with some trepidation but it turns out to be a really striking colour.