I ordered the small because it was $20 cheaper at the time than the medium. I can just barely squeeze into it, but once on it's very comfortable! The part on the front with the silver pattern is mesh, but it doesn't look very sheer when wearing it. My only issue is that because I ordered a size to small it's a little difficult to pull on without feeling like I'm going to tear the straps in the back... I think the sizing guide is probably pretty accurate, and a medium would have been perfect if I wanted to pay the extra amount. For reference my measurements are 36" 26" 36," and I'm 5'4" tall.