Bought one of these to try something different from Under Armour, very happy with the purchase. I'm 6'0", 205 lbs, with broad shoulders, so generally go XL even though it's a bit baggy in the midsection. Bought the XL and it's a great fit, fits well up top, not too loose towards the bottom. The thumb holes are a nice feature as well. Keeps me plenty warm underneath in mid teens temps, and I've also used it running outside in low 30s. Awesome shirt, am thinking about buying another!