I bought a small and I am 5'6.5" and 130 lbs and I agree, it fits with lots of layers underneath it as well. The sleeves are barely on the cusp of being short for me, but I think I have long arms. I realized that if I bought the medium, there are cinches in the waist that could make it fit better, however, I decided to stick with the small. I was disappointed to see that there were no thumbholes as well, but I did like how there is a stretchy elastic cuff to make sure wind and the elements doesn't blow straight up your arm. I also haven't had the chance to test it in the blisteringly cold Chicago winter yet, but I really like it so far.