I'm a woman, rather tall and somewhat slender (5'9 135 pounds) and the medium fits me perfectly.  It's just a tad long in the sleeves for me but that's actually okay too.  I was also very happy that the color was much less metallic and a darker shade of olive than the picture.  It's amazingly soft and light.  I'm not sure about the warmth yet - I live in So. Cal.  I definitely recommend this jacket though.  It fluffed up nicely after a couple hours (but not too much) for my taste.  It was also noticeably less expensive than a woman's comparable jacket.