Im going to give the 4/3 a test this weekend. I busted the zipper on my winter suit last weekend. I can still get it to work but its a bit of a hassle. Im thinking with my 4/3 and hooded vest I should be fine. Good to hear other people have gone to 4/3s as well. Im pretty excited to get into a suit via the back and not worry about the chest zip again until next winter.