My experience with wetsuits started during Open Water lake dives in a light snow storm. I tried 4 different suits that weekend, until the LDS came up with a XS Scuba 7mm farmer john in 4XL. I purchased this suit after the class. It's tighter than I'd like through the shoulders, and way baggy in the butt, but it was a rack grade suit that fit. I've since bought a replacement of the same model, and a 3mil shorty also XS Scuba 4XL for temperate water. My requirements were simple -- warm enough for 38 degree water, big enough to breathe in. If I absolutely had to, I would have gone custom, but fortunately I found a big enough suit from XS Scuba. My major complaint is the horrendous amount of ballast I need to have a safe safety stop, which leaves me significantly negative at 100+ ft for the beginning of the dive. I've since bought a DUI drysuit, but this past summer for RD class I opted for the 7mm wet.