I tried another Henderson on in the store, it wasn't the Hyperstretch but their Medium fit like a glove. When I went home and looked at their sizing chart I found I was at the high end of their medium (39 chest, 33 waist, 38 hips 5'11" - 1 inch over 5' 10" which the chart says) I'm actually perfect for a Medium-Large but I've never seen anyone selling a Medium-Large. Just Medium or Large. I decided to go with a Hyperstretch and ordered a medium. The thing fits like a glove except in one spot, right at the very base of the zipper in back there's pretty good size pocket of air. Since were I live in Seattle (this suit is for warm water diving) I only wear a dry suit, I haven't worn a wet suit in several years. I forgot if this little pocket at the base of the back is normal for a wet suit (it dissapears of course when you aren't standing straight up). It seems like the suit is pulled tight enough in the back that it prevents it from hugging my lower back just above my butt. But the curvature going from the top of the but to the lower back is so extreme there, I don't see how a properly fitting wet suit wouldn't have some airspace there. Otherwise there is absolutely no airspace anywhere else in the suit. I figured if anything, especially with the Hyperstretch, you want to go with the smaller size when you are borderline. This thing was so expensive, I just need some peace of mind from someone that knows wetsuit fitting.