Sizing
It does shrink in length just a bit. I'm 5'11" 200lbs and the medium fits good. It's a little baggy before washing and snug after.

Feel
First, these are not thick-puff style thermals. They are thinner and easy to wear under clothes. While not super thick, I still felt warm in the suit even just wearing around the apt. I don't use the rear flap so can't speak to its effectiveness. Wish they offered more color choices.

Cons
My one and only complaint are the buttons. They are a bit flimsy. I've had to sew two back on. While not a huge inconvenience, it's still a bit disappointing for a garment needing buttons sewed back on after only two washes. It would have gotten 5 stars if not for this.