I have a pair of these shirts (along with a long sleeve and zip-up) now and they are great if you are willing to take on the slightly higher maintenance requirements. I am 6' and about 170lbs (with a shortish torso) and the medium fits me great. I wear it for everything, layering under warmer gear, by itself casually and on long runs and it works everywhere. Soft and no scratching, doesn't stink even after a couple runs back to back without washing.
Speaking of washing, I wash it cold and make sure to give it a little stretch before laying out on the drying rack and it has not shrunk on me. Get yourself one (or a couple and don't look back.)
I really love that these are made in US and I love supporting a company local to Salt Lake!