I have owned the patagonia down sweater and other Arc gear and I was looking for something with a little more durability for outdoor climbing, hiking/ base camp. This jacket is about the same weight as the down sweater but is much warmer and constructed beautifully.
The only exception, which I have seen reviewed on other sites, is the zipper that will release and move down spontaneously if the jacket is half zipped. Arc' has this on several products I have recently purchased and they say they have it so that this jacket does not rip under tension but I think it indicates cheap zippers in attempt to save weight. It is an annoyance when actually climbing or moving around.
Other folks have reviewed the warmth and comfort and it is incredible and the fit is trim meaning that this can be layered with a shell for true waterproof comfort and protection. I was debating an XL but L for a 6 foot 2 frame was perfect. The covering is "ripstop" but is not as thick as the thorium jacket meaning that there is lighter weight with the possibility of less durability. The covering however is much more significant then the patagonia down sweater and other lighter weight down jackets.
I know for climbing and base camp activities at high altitude this will be a great addition if the zipper situation is not too annoying. At single digit F temps this is just awesome. The hood is a key piece that is also wonderfully constructed. Large pockets and a great fit.