All that you're gaining by the stepin, rather than just a hooded vest, is covering your backside and upper thighs. When I start to get cold, I feel it in the upper body, around my core area, not my rear end or legs. A hooded vest under a full wetsuit fits very snuggly and doesn't move and allow water to flood in from kicking or moving your body around.
If you get that cold though, maybe consider a dry suit?
makes sense, however i do like the zipper, which makes it alot easier to be removed.
however i do have another question. does it really matter if i get 7 mm or 5mm hooded vest? i know 5 mm is enough for me, but what if i go with 7mm ?
and sadly, dry suits are out of the question for now, too expensive ^^ and the water i dive in is like 22-28 c. sometimes i dont need a hooded vest.
thank you