I had the opportunity to test this jacket in some sub-zero Chicago temps over the holidays. It was good down to about 15-20 degrees standing still and close to zero active (chopping ice off the walk and shoveling snow). I felt that the thing that really held the jacket back was the lack of a waist hem drawcord. The elastic waist just didn't do the job in windy conditions in keeping cold air from making its way in and chilling me. I know this would add a little weight, but it would increase the jacket's utility. Either that or increase the length by an inch or so. Or well a shell jacket, I guess. The rear hem is not dropped, so I got some exposure when bending over the snow shovel. The fit is really snug. The large fits me well (5'10", 170) but as I said, it could be a bit longer. Arm length was fine and the neck fit snugly enough minus a drawcord that I didn't feel like any body heat was escaping that way. Around town, (I got several compliments on the appearance) the shell fabric is durable enough, but I wouldn't wear it w/o a shell anyplace it might encounter a stray branch or rub against some abrasive rock. It's somewhat water resistant, but really just enough to give you time to get a shell jacket over it. I wouldn't expose it to wet snow for very long if you want to stay warm. Light and compressible, it's a great layer to bring for instant warmth in cold weather camping/hiking/snowshoeing et al.

Extremly light and stuffs up to a small softball. If you need just a little warmth, this is your jacket. However, it is very short around the waist, expecially in back, with no draw cord. The material is very fragile and is easy to tear, or snag. This is not a long term jacket,

This is a must have whether you spend lots of time in the outdoors or just live in a cold climate and use it for running around town.

As another reviewer said this jacket is big on warmth and very lightweight. If your packing it for a backcountry trip you won't even know it's in your pack. But you'll be glad you brought it along when it's time to unskin at the top. It's a great way to eliminate those "unskinning chills".

The only downside to this jacket is that the ripstop nylon is ultralight, which means it's likely to be sensitive to abrasions. Don't carry your skis on your shoulder if this is your outer layer. You might not like the results.

I've tried the Patagonia, sent it back, way too bulky and short, I've tried the Mont Bell UL, sent it back (very nice but too much of an Inner Layer) This Alpine Light is where it's at, although I got the parka which I don't seem to see on BC.com!! This is also the best jacket I've ever owned, Its cut is superb, I'm 6'3" and around 200 lbs but pretty lean an athletic, and the only gripe I'd say I have is it could be a tad bit longer in the torso, but again I have a long torso and its def not bad enough that I would send this one back, b/c the rest of it makes up for it and fits like it is custom cut. I called and spoke with a rep at MB and he said that their LG down jackets run one inch shorter in the back the the XL so its very similar, I think it was 28' from neck to waist. It's warmth to weight ratio is absolutely stunning, and when you put it on you cant even feel it's there. 10/10 Great value!

This is really the best down piece MontBell makes, since it's just a bit tougher than the UL, but warmer and very close in weight. That said...I have the Parka, with the insulated hood, and I would recommend it over the hood-less Jacket (thus the 4 stars out of 5). There is nothing like pulling it out of my pack at the end of a ski tour, when I am waiting for someone to grab a car from Big Cottonwood. It fits easily under my hardshell, and stretches over my softshell. Comes with its own little stuff sack too.

I agree that it does run a bit small. I'm 6'4" and the large fits great everywhere but is a little short. I´m currently wearing this jacket in an internet cafe in Quito, Ecuador. We are heading to Cotopaxi today and it will be on my back the whole way. I have already climbed in it on Cayambe, which was very cold. Its super warm and packs down really well. Great jacket and another great product from Montbell.

This jacket is awesome, but like many of the reviewers I agree that the sizes run a little small. I'm 5'8" and around 140 lbs with an athletic build and long arms, the arms are long enough but it is a little snug around the chest and shoulders. I debated sending it back for the next size up but then the waist and stomach area would probably be much too large. Overall a great jacket and very warm especially with a shell over top.

This is a great jacket and probably the best I've owned. I'm about 6'1", 175lbs and a large fit great. I used it on a backpacking trip in Northern Georgia and it kept me very comfortable at comfortable at camp on a couple of nights in the low 20s. It's super light and compresses very small. I took the stuff sack it came with and was able to put some dry socks, gloves, and a hat in there with the jacket (probably will get a waterproof sack for next time). It's probably not as light and compressible as the MontBell Ultralight. The nylon shell is studier and I wear around town when it's cold out at home.

I can't help it, I have to give this piece the full five stars. I prefer the hood on the parka version, I think it adds a ton of warmth, but besides that, this jacket is nearly flawless (and some people don't like hoods in their insulation layer). Insanely warm, weighs next to nothing, packs down tiny. A few more specs: zipper garage at the throat, internal drop pockets on both sides, elastic cuffs (but without the horrible wrinkles some cuffs have). Sizing is spot-on, i.e. size up from tnf (5'11" 150lbs, medium fits perfectly where a small in north face is required). I decided on this instead of the U.L. MontBell jacket, and I have to say that the 15D nylon on the U.L. might have been a little fragile. As it is, I expect to get a lot of use out of this jacket, construction is immaculate, very low tolerances on the seams etc.
Fleece is dead, long live down.

I have several down jackets. At 6'2" / 175 this jacket in Large fits me best by far. The sleeves are just right so they must be about 35" from the center back. The length is kind of stylishly short so it would never cover your butt. If you're not slim then you'd probably prefer other brands like TNF or Marmot or Helly Hansen...

The nylon in this jacket is 30D so it's actually quite burly. Like other MontBell stuff the DWR is highly water resistant (water beads up) but not so breathable. That's a pretty good tradeoff since likely you wouldn't wear a jacket this warm while doing anything aerobic anyway.

The neck is lined with fleecy stuff that some people like. Personally I would have preferred the same nylon as the rest of the jacket--it's smoother and lighter. The pockets are nylon lined but as is pretty common there is only down on the outer side of the pocket.

All in all I definitely recommend this jacket.

Great light down jacket (too warm for 35+ degree weather though). No where near as bulky as those other down jackets. XL fits more like a L Tall (6'4" 220lbs).

First off let's do sizing I am 5-10 165 and the medium fits me snugly, it gets a tad bit tight when I bend over for something, but I would rather have a snugger fit on a down jacket to eliminate a little of the marshmallowness. It also is not as long as a lot of other down jackets, it feels like it's an inch shorter than normal. I originally got this for a mid layer for skiing but i found out that I started baking, even when it got around 10 degrees, so I will only use this as a mid layer when it is damn cold. It still surprises me how light and warm it is, and it stuffs really small, and is awesome for winter camping (once you arrive at your destination. I have found that every time I use the stuff sack I have pull back in a few feathers, so only use it when you need to. Also This was the best looking and best fitting, as far as cut goes, down jacket that I tried on, I don't look like a marshmallow, and it's still thick enough to walk around SLC at night when it's 10 degrees. The only thing that I don't like about this jacket is that it doesn't have a loop to hang it on a coat rack, it boggles my mind every time and I almost deducted a star because of it

Compared to a down jacket that really adds an insulating layer, this thing is like two layers of paper filled with a bit of toilet tissue. It needs about 2 ounces more down to really work the way you'd expect. Not puffy. We want puffy.