Not as impressed with the shirt as I was with the tags and the look of the inside. It fit true to size, the length is really nice. It's a good layer, but I didn't really notice anything special with the awesome looking Omni-Heat. I used it while sitting, not moving to try to keep warm and I also used it while working out. I used it as a base layer, a single layer, an outer layer... It seemed like a typical layer.