Not Sitka gear, but I do own a Rivers West jacket. It should be re-named Rivers WET! If you are stationary, it will keep you warm, HOWEVER, it holds sooo much water on the outside. If you move around and perspire, it will hold that on the inside.
Once when I was out moose hunting and returned to camp, my jacket was extremely heavy and took a long while to dry. This is one brand name I will never buy again.
