I'm about 5'7", 175 and the Medium size of this sweater fits me well. In terms of style, this is a great piece that you can wear to work, afterhours, or out in the wild. I would characterize the fabric weight as medium-heavy.
Functionally, I find that this piece works as a solid midlayer underneath a shell down to about 20F or so. You may be able to get away with it at slightly lower temps if you are a really hardy soul.
People in the market for a cheaper, slightly lighter sweater should probably look at the North Face Fairfax. Be aware that piece runs HUGE versus the listed size.