I never know what size to order in S+M because I like a comfortable fit, not too tight. I am 150 lbs, 5'5" tall with a DD chest, and find I am between sizes quite often. I ordered this in the M and am very happy with how it fits. There is lots of give in the material and the stretch is just right. I may shorten it slightly as it is longer than I usually wear, but the wrap around effect and slight opening at the front do help it feel less "frumpy" even if I were to leave the length as is.
Rated 4 out of 5
Rated 5 out of 5
Rated 1 on a scale of minus 2 to 2, where minus 2 is Runs Small, 0 is True To Size and 2 is Runs Large