This jacket rocks! I bought this at the last minute before a trip to ski on Mount Washington in New Hampshire. This shell was a fortress against the high winds and kept my warm in the low teens with only my R1 and a wool baselayer underneath. The biggest surprise was how breathable the Active Shell is. I didn't even have to open up the pit zips while breaking trail on a boot pack up Hillman's Highway in a foot and a half of fresh POW. I was able to click into my skis and head down without changing any layers.
I am 6' 165 pounds and I found the Medium true to size. Its an athletic cut (unlike my old Patagonia Rainshadow which made me fit two fleece jackets and my big down puffy underneath) but it has room to layer. Keep in mind the tag has Large written on it, but that's european size. just below, it says US-Medium.