I have gear tested the MHW Nitrous jacket as well as the Patagonia Down sweater, and must say they are some of the finest lightweight insulation out there.
The Nitrous is much narrower in the hips (you skinny folks would love this jacket). It has has more stitching.
After using the down sweater for a season, I decided to sell it. I already have an R2 jacket, and a BC.com Siphon Primaloft jacket, and needed something warmer. After 25 degree weather with the Down Sweater, I wish it was warmer.
I replaced it with a MHW Phantom Down Jacket, which is 4 ozs heavier but MUCH MUCH warmer.