The Western Mountaineering Flight Vest is just what you would expect from the premier down sleeping bag maker in the US. It weighs less than the Flight Jacket, coming in at about 5 oz. It works well as an insulating layer for hiking, especially helping to retain heat at resting points. It also can really help out if your sleeping bag isn't getting the job done keeping you warm at night. If you are looking for a lightweight, compact, & highly insulative layer, then look no further. This is definitely one of the best down vests that you can get.