Right, but it's the undergarments that make the buoyancy of the dry suit. I guess I could try it again with less underwear, but this seems like a good solution. Especially since I'm only using the suit in 6 feet of cold water, I'm not worried too much about compression!
Yeah, that was my point. If the water is warm enough to dive a 5mm wetsuit comfortably, then with a 3mm compressed neoprene drysuit, you should need very little in the way of undergarments. So, very little extra weight.
But, you got a suit that you're happy with and that's all that matters. And, yeah, at 6 feet it's probably not going to compress and lose its warmth any time too soon.