I love this thing.  It's really soft and comfortable, and most importantly, it is cut correctly.  I was concerned that it might be cut too shallow in the arms, but it definitely wasn't.  I'm 5'7" and 135 (with most of that in my hips) and a small fit me perfectly.

As another reviewer mentioned, the fabric does tend to cling a little, so up-sizing might be a good idea if you want a little more coverage.