Great
For an 800 fill down jacket this is perfect in terms of space. Very thin, yet very warm. Perfect for many conditions. I do a lot of mountaineering and this is perfect for layering under shells and even under 300 weight fleeces. Excellent jacket!

Geat Jacket
Excellent warmth to weight ratio

Mountain Hardwear Men's Nitrous Jacket
I investigated several different down sweater jackets. I really like the fit of this jacket. I'm 5'9/170 and the tapered fit of the large worked well. I purchased the Patagonia Men's Down Sweater in a large but it was very bulky in the belly area and the medium was to small so was returned. I have worn it in the low 40's as a slip on and it works great, even a little warm. The con's are no zippers on the pockets and the cuffs on the sleeve are a little loose and could use elastic or some other material to tighten it up a bit. If not for these last two items I would give it 5 stars, it's a great(very) light weight coat and would recommend.