Just a couple of things to consider when choosing a dry suit:
1. Buoyancy swing in a regular neoprene suit will still be an issue. Not as much of an issue in a compressed neoprene or a trilam suit.
2. Weighting may be more or less than a 7mm wetsuit, depending on undergarments and suit type. When I was diving a compressed neoprene suit I used about the same amount of weight as a 7mm wetsuit. Now that I am in an Aqualung Fusion I use more, but I have on thicker undergarments and stay warmer than I did in my old suit.
3. Consider zipper placement. I STRONGLY suggest going with a self-donning suit. It is really annoying to have a back-zip.
4. Consider zipper material. Plastic zippers are cheaper and more flexible, and sometimes more comfortable under BCD straps. But they will wear out faster than brass. I prefer brass.
5. Consider the seals. Personally, I like silicone seals the best. They are robust, stretchy, and comfortable. Latex seals need some more babying. Some people like neoprene seals. They are usually pretty comfy, but you have to make sure they fit well from the start. They will eventually stretch out and then you'll have to replace them, and that means sending it off to get done since they are glued on.
6. Condensation. Depending on air temp and humidity, water temp, and how much you sweat, you may get a fair bit of condensation inside of a trilam suit. I get a lot of condensation in my Fusion (which is essentially a bilam with spandex/neoprene outer shell). I barely got any condensation in my old compressed neo suit. A good wicking base layer is essential in a trilam suit.
Good luck!
