Just switched from UA to wool. Bought 1 Core4 1/4 zip and a First lite mock T. Went from 3 to 2 baselayers. First lite is the better of the 2. Much more comfortable and warm. Still like UA. First lite wool, core4 wool, cabelas e.c.w.c.s heavy weight, UA infrared hoodie, cabelas merino vest, UA infrared jacket. All super thin. 6 layers in all when it's super cold.