I have had both for about 15 years now. I find that the a farmer john wetsuit, underarmor shirt and non-gasket semi-dry top is the most versitile. It is usable up to 85-90 if you are getting sprayed and down to around 55-60 degrees if relatively dry. One big advantage is that it protects from abrasions especially in rough weather. It also "sticks" to the tramp in those unplanned wild-thing moves. Even a beatup old wetsuit with holes remains servicable.

Dry suits are great below 60 degrees and allow you to layer to any temps short of hard water. The are much more slippery on the tramp and protect less from sidestays/boards/blocks that you abruptly come into contact with. I have found the gaskets only lasting a few seasons and are expensive to replace.

A shorty is nice to have for anything above 85 mostly for the body protection.

I am realitively temperature tolerant... my wife would be in the drysuit in anything below 85 degrees.