I work in the outdoor industry, so much of my wardrobe consists of fleece - 1/2 zip fleece shirts to be exact. I picked up this Shak Lite almost on a whim and have barely taken it off since receiving it. I love the color (earthy grey with blue trim), and the contrast on the collar dresses it up just enough to take you from looking like an outdoor bum to an outdoor professional. I'm 5'10" and 125 - the small fits great over a light base layer or a light base + tee, and is still slim enough (without being tight, by any means) to pile more layers atop. Consider sizing up to allow for a mid-weight layer beneath.