joe, it's not all skishing. there are some rocks that you just can't reach with conventional methods. the added safety of the suit's buoyancy is also something i am considering. walking? there are no good spots you have to walk to in RI!!!!
Goose, Harvey makes an extra insulator for underneath the suit. another 3mm of insulation. might make a 5mm a more practical choice.
http://www.harveys-divesuits.com/accessories/vests.asp