- crushed neoprene is a vastly better insulator than tri-lam material. If I wanted to wear this suit in warm water that would not be good. But, for use in cold water, it means I wear less undergarments than if I were in a tri-lam. That means I carry less weight. Win, win.
Of course, crushed neoprene is a "vastly" more buoyant material than trilam... so you'll carry MORE weight because of that. Net-net, you may well be carrying MORE weight with your crushed neoprene suit than someone diving a trilam suit. I know the folks I dive with who have crushed neoprene suits carry a lot more lead that I do... which is none, actually.