These shirts are awesome, but I am not quite sure what Ibex was thinking with the sizing. I wear a medium in just about everything (6'1", 170) and the medium for this fits like a skin tight muscle shirt--wearable, but not always comfortable. Don't get me wrong, I prefer trim fitted baselayers (and I've been known to size down to a small to achieve this once or twice), but this one is a little ridiculous. I bought a large, and that fit much better, still an athletic cut and trim enough to easily layer over, but it doesn't feel restrictive like the medium can. Other then the fit these are spot on though, soft, well proportioned cut for a tall lanky person, and they look great. I use mine a bit more casually because I prefer a zip neck rather then a crew cut for keeping warm outside, but these have the technical chops for when you need it without that techy look--breaths great and wicks as well as any other wool layer. If you want something that can transition seamlessly from the sloops to the bar then this is your best bet.