Arc'teryx Atom LT Insulated Jacket - Men's

I’ll preface this review with my cut and paste statement that I work as a backcountry backpacking guide in Yosemite National Park. Nearly all of the products I take the time to review have seen at least a half a season, if not more, of use... and I’m committed to not bothering to write a review until I feel like I’ve really gotten to know a product. I never thought I’d bother to write reviews, but I’ve recently decided that since I’ve spent so much time over these last many years reading reviews, and finding a tremendous amount of value in articulate and well-informed opinions, that I wanted to give back to the community. So, with that being said, here we go...

Another initial disclaimer specific to jackets, I spend most of my time in a down jacket while guiding in Yosemite. The minute the sun is down I have it on, till I'm in my bag, then on when I'm out in the morning till the sun is out.

That being said, every other moment I need an insulated jacket the Atom is my go to. I have an LT, an LT hoody, and an SV. The LT hoody version of this jacket is probably my favorite, as the hood adds a little more usefulness in a wider range of conditions, but that's really knit picking. The LT is incredibly useful, having a purpose in the widest variation of temperatures and conditions. Aside from pouring rain, when I would throw a hard shell over it, this jacket does it all. The LT with a short-sleeved base layer, is good down to the 40s, even lower if you're moving and generating heat. If it weren't for the fact that I save about 3 or 4 ounces by going with a down jacket that costs twice what this jacket costs... I would use it for everything. However, I like playing the weight game when I'm packing, and am always doing my best to lighten my load.

Setting those 3 or 4 ounces aside, this jacket, in concert with a nice hard shell and base layer, can do it all. It packs down wickedly small, is very comfortable (the outer shell feels great), breathes incredibly well while moving (thanks to the paneled sides), and is very, very light. To repeat myself, the only single condition where I'd suggest another jacket would be if you're trying to get as much as you can for weight and packability versus warmth, where down has an upper hand.

If you need a slightly warmer jacket (sitting around or belaying in below freezing temps) grab the Atom SV. Its also a killer jacket. If you want more flexibility then grab the LT hoody. Its immensely useful under many different situations.

I can't say enough about this jacket, or the other versions of it. I can't imagine a more useful layering piece.

I primarily use this as a mid layer for resort skiing on very cold days, and it's great for this purpose. The breathable side panels really help to maintain comfort under a shell. At a slightly pudgy 6'1" 185 lbs, the large is a pretty snug fit for me (as is typical with Arcteryx). This works out well as a midlayer, but if I wanted to use it very much as an outer layer I'd probably want to size up.

The Atom LT is a great piece for anyone. I'm usually a down guy, but Arcteryx's has done a very nice job with their Coftlot insulation.
The reason this jacket is so nice, is because it can be used as a technical mountain piece, but can also be worn as a causal piece as well. It doesn't look too technical to wear around town.
There are two things that bug me with the jacket. The side panels allow too much wind and air if you are using the Atom as a top layer. Also, there are no pull tabs to adjust the waist. This also allows too much air to come under the jacket.
I try to commute everywhere on bicycle, and this jacket is great for short commutes in the low 40's.
I am 6' 135, and I wear a medium.

I've ordered, and returned, two of these jackets so far.

The good: They are fantastic in build quality and fit, and in short trials walking the dog (tags still on) they are very warm. I'm looking forward to getting my third one.

The bad: the color pictures on the website (and on Arc'teryx's website) are not accurate indications of the color of the jacket. For example: Squid Ink, which looks to be a nice blue/periwinkle, is actually a deep purple; Tibetan Red, which looks like a nice dark red, is also more purple than red, with a ridiculous light orange lining.

Not being man enough to pull either of those colors off, I'll be placing my my next order for the black version. Hopefully the third time will be the charm.

This is my go to jacket for all year activities. I use it alone when it is mild and when it is cold I use it as insulation under a shell. It is perfect to wear most of the year when you need some warmth. When it is around the 40's-50's it is great to wear alone because the fleece panels on the side allows it to breath well. In the winter it provides great insulation under a shell, but you would want something heavier if you you are stationary in the dead cold. If you are active it is fine. There is no hem cord around the bottom and the wrists have a spandex part to keep them in place. Alone, it isn't amazing when very windy becuase the fleece side panels lets the wind in. It has a DWR coating to fend off light precipitation, and the coreloft insulation is pretty stinking close to down. It's very light and warm. I am 5'9" 140lbs and wear a small. It is nice and snug but if I want to wear more than a base layer and a light fleece under it I would size up to a medium. It's worth noting that on me it is just to my waist in length so if I wear a longer shirt under it it pokes out, but that would probably be resolved if I had a medium. I wear this around town and for technical pursuits and it fits both functions flawlessly. This is my favorite jacket out of the many that I own and it is definitely a must have in your arsenal!

This jacket receives my praise on so many accounts that even at full price, it feels like a bargain.

To better understand my use of the jacket, it may be worth noting that I live in a coastal desert region. My need for a jacket is limited to cold nights and mornings, a few short winter months, and travel to colder regions. That being said, the Atom LT is light, compressible and breathable, which warrants having it on me much longer than I would a heavier jacket. This is one of the main reasons for my purchase.

Others have mentioned that the piece does not appear very "technical" while still offering great performance. This jacket suits a casual setting just fine. Not everyone will care about that, but kudos to the bird for designing a jacket that excels in both performance and aesthetics.

Lastly, I am probably one of Arc's huskier customers, and I don't always get along with clothing labeled "athletic fit." The XL fits me JUST right and with excellent range of motion. It is like wearing nothing, and I don't look like the Stay Puft Marshmallow Man, which is a good thing..

Money well spent.

Liking this one. Primarily bought to Layer under Beta AR for skiing, but is great for any autumn/winter out and a bouts, I slip it under a gamma lt if I want a bit more rugged. Fleece sides work well to keep it all close, but you can feel a little heat loss though them.

5'9"' 80 kg and medium is fine.

Liking this one. Primarily bought to Layer under Beta AR for skiing, but is great for any autumn/winter out and a bouts, I slip it under a gamma lt if I want a bit more rugged. Fleece sides work well to keep it all close, but you can feel a little heat loss though them.

5'9"' 80 kg and medium is fine.

This is my go to layer for skiing on any day below 40 degrees F. I can understand the criticisms of some of the other reviewers here, but because of the way I use this jacket (which might differ a bit from them) it works perfectly for me and I give it 5 stars.
I wear this under a shell jacket and it has finally solved my layering problems for the first layer. My problem when skiing is I tend to be either too hot or too cold, and sometimes both if that makes any sense. My base layer also needs to be multipurpose so that I have options when adding another layer. So I need a layer that gives moderate insulation but breathes very well. This is where the Atom really shines. I can have it zipped open when I'm too warm, and then it feels like nothing is on me. The side panels are fantastic. When it's cooler and the Atom is zipped, it gives great insulation and is the only layer I need down to about 20 degrees F (depending on wind and sun conditions). But the real surprise is what happens when it's colder. My second layer is a Patagonia Down Shirt. When it's not too cold, the down shirt is over the Atom jacket. This way the combo breathes more and gives less insulation. When it gets even colder, I reverse the order and wear the down shirt under the Atom. This way I get more insulation and it breathes a bit less. With all the possible zipper adjustments of both layers, it's easy to handle anything down to about 5 degrees F (again depending on wind and sun). When it gets mega cold I add a Patagonia down sweater. Due to its light weight and packability, it's easy for me to stuff the Atom in my backpack, even with a lot of other gear there. Another nice feature is the pockets, which work quite well for me. When the outside pockets are zipped open, one gets extra breathability. I use the inside, chest level pocket to keep my cell phone from freezing up. If it gets to minus ten F with heavy winds, I can move my cell phone and put a body warmer in the chest level pocket.

Where I differ from other reviewers is perhaps how I wear my Atom jacket. It is true that wind can blow in the sleeves, but this never happens to me because the Atom is under my shell. It is also true that wind will blow up from the bottom of the Atom because there is no waist cinch. But if it is warm then this is an advantage, and when it gets colder I always tuck my layers into my ski pants, hence no wind problem. (My core tends to easily get very cold.) Yes, it looks lame tucked in, but hey, it's underneath my shell so nobody sees it. Perhaps Arcteryx might want to reconsider the length of the Atom, which I think is a couple of inches too short. But because of the way I use it, it's not a problem for me.

I got this to replace fleece for layering under a ski shell. It's much more compressible and a lot warmer since it's really wind resistant. It could stand on it's own as outerwear in pretty bad weather, as long as you keep moving.
Nice tough-faced fleece up the sides and under the pits lets out just enough heat and moisture that you don't feel clammy during exertion in cold weather. Nicely placed, warm pockets. The collar is not bulky and is kind of short compared to some fleece jackets. This makes it nice when layered under other shells with collars. The cuffs are very low profile spandex-like material with very little bulk. Jackets slide over the sleeves very easily because there is no velcro tabs to snag.
I had avoided Arc'Teryx for years due to the price being high and the manufacturing being moved overseas. So far the fit and finish seems very high quality. I still think the stuff could be priced 5-10% lower, otherwise I'd give it 5 stars.