This vest is really warm. I actually bought a medium and large to try out which one fits better. Turns out, when the vest is zipped up, the medium is a smidgen too snug and the large is too big. I wish there was a sizing in between. However, the snug fit of the medium also makes it warmer. I'll be wearing this unzipped most of the time -- since it looks better unzipped -- unless it's really cold.As to the quality of the vest, the Calvin Klein name says it all. Top notch styling and quality. The stitching and the material used is impeccable. And the pricing is incredible, too (I bought this from Amazon direct for ~35).