Great All Around
Jacket fits well. Cannot really say as to warmth as we have not had cold weather yet, however, Thinsulate insulation is probably same as had in previous ArcTeryx jacket and was just right. Fit is good, however, collar is somewhat high. I guess this is due to having a hood that would cover a helmet. would recommend this jacket.

Perfect Jacket for a Bigger Guy
Being a bigger guy around 230, I wanted a windproof, waterproof and lightweight jacket with a longer cut as well as room for a possible under layer if need be. The XL is just perfect for this! I also made the pick for the stow away hood which comes in handy when out skiing on days it isnt snowing. A coolness factor about the insulation (prima loft sport) is that it is waterproof and retains its ability to trap heat after being wet. My favorite jacket!

A teriffic jacket...but
I bought this Fission AR because I have a Fission SV and love it, but wanted the lighter version with the hide-away hood. Well, I got what I wanted- mostly: The xl AR jacket weighs 896g compared to the xl SV jacket at 1100g and the hood does hide in the collar. When the hood is zipped into the collar though, it makes the collar stiff and bulky and it won't lay flat, nor can you move it away from its position against your face. The remedy is to keep the hood OUT of the collar and then it feels OK. Otherwise it is every bit the jacket that the SV is, less about 200g and less $100... it is just as warm, just as waterproof and just as comfortable. BTW, I usually get black but I could not in this case and bought the "Dusk" color, which in this case is a beautiful and subtle dark blue. I like it better than black. I'm not going to complain about the high cost of these items--- they ARE pricy and they may not perform better than lesser priced competitors, but they last longer and the higher quality workmanship and materials are totally obvious.

Just what I wanted
I have several very warm, very heavy Gore Tex jackets/parkas. I have been looking for something Gore Tex but lighter with some kind of lining. The Fission AR is exactly what I wanted. The jacket is perfect for 20-50 F. Fit is very accurate. I'm 5" 11" and 165#. Large fits great and I can easily put a fleece under the AR if I want more warmth (for extended times below 30F). I wish it had two more zippered pockets but the interior mesh pockets are very handy.

Great jacket for all around use
I bought this jacket about 3 weeks ago and have been completely satisfied. I live in the city of chicago and am frequently walking around from place to place; this jacket has done a good job keeping me warm and comfortable when in between outdoors, car and indoors (throughout the month of January). I have a fairly long torso (am 5'11 with short legs) and the jacket's back bottom comes about mid-way down the seat of my pants. The front is a bit shorter as its fitted this way. On the top, when the jacket if fully zipped it rests just below my nose if I tuck my chin down (just about to my lips when my chin is in normal position). The back top of the jacket covers my neck completely. The jacket is very stylish and looks good on. It is also very comfortable to wear and packs into an unbelievable tight space if you're going to be tightly packing it for a trip. My only suggestion would be to incorporate more pockets. It has two inter spots to store things (one on each side where the zipper comes together in front bottom) and two normal hand pockets in front bottom where the zipper comes together. If it had a sleeve pocket or an inter breast pocket this jacket would have it all. In all, even without the extra pockets this jacket is still great for everyday winter wear if you want something that is pretty warm given its weight, comfort and style.