After much research between the Patagonia Down Sweater and Nitrous Jacket- I went with the Nitrous Jacket. I liked the slimmer cut versus that of the boxy cut of the Patagonia down sweater. Exceptional jacket, Sapphire (awesome color) but the large was too tight around the back of shoulder and under the arms. Tried XL and was too large. I am 5'10'' @ 188lbs -wear a size 42 regular jacket. I normally take a large in MH but unfortunately this cut in this style did not work. So I returned it for a sub zero in large. It would be great if Mountain Hardwear would re-work the cut on this model.

I was looking for a warm insulation layer and narrowed it down to this and the Patagonia Down Sweater. The baffles on the Patagonia seem larger and it seems slightly warmer. But the reasons why I ended up getting the Nitrous were:

1. Fit. I'm 5'11", 145 lbs and this jacket fits much better than the Down sweater. I bought a small and for the same fit on the Patagonia I would need a XS but then the sleeves become too short. The cut is also longer on the Nitrous. However, don't expect to be able to wear more than a baselayer underneath. It'll become too tight. Or buy a size up.

2. More streamlined for layering. I bought this with the intention of wearing it under a shell. The Nitrous isn't as puffy as the Down Sweater and it fits alot nicer underneath my MH Hairpin jacket. With the Down Sweater you can feel it bunch up at the armpits.

3. Features. I ended up getting the Nitrous with the hood, which unfortunately can't be found on BC. It has a convenient chest pocket that the Down sweater does not have. Also compared to the non-hooded nitrous, there are zippers on the handwarmer pockets plus an internal pocket.

This piece competes with the now super popular Down Sweater by Patagonia, however its cut for certain folks. I'm no fatass by any means (34 waist), and the Large was too tight around the hips. Its cut for you skinny folks, more so than the Patagonia. Its cut longer though, which was something I wanted in the Down Sweater, and has thinner baffles to prevent shifting of down. Pros:

-GREAT arm length
- UBER light, its lighter than the Patagonia
- Comes w/ stuff sack
- Packs down smaller than the Patagonia

Cons:

- too tight around hips (32 waist and smaller)
- NO INTERNAL POCKET, but has a handy chest pocket
- Elastic cuffs (I hate elastic cuffs, cause no matter what they stretch out)

Overall, a great alternative, if you are a skinny, lanky mofo, this is your choice for a premium cold weather midlayer