my wife and I have rescue certs, ppb, and about 70 dives each, with a mix of great lakes cold water and warm vacation diving. We boat dive, and shore dive, about equally. We bought Seaskin trilam suits this winter, and just started diving them. We chose to not take the drysuit course. We did however, borrow the course material from a friend, and completed the book, tests, and video work completely. We only have 3 dives in them so far so take my comments for what they're worth...
The 1st time out, was in a local "pond", max depth of about 25 ft. Easy beach-like shore entry, and chosen for the benign conditions. We had plenty of time to get ourselves sorted out on shore, and had tried on the suits a few times at home, to get used to the dressing process. We complicated things a bit (or a lot) though, as we were using steel plates instead of carbon, and had moved from aluminum 80s to steel hp100s during the winter. Also swapped to jetfins for the added weight. Basically, we broke all the rules about making big changes all at once, but it's just way it was happening. We hadn't changed the overall configuration we dive in, but all the "materials" had changed, in favour of heavy gear = less lead.
First things first, a proper weight check. We had over estimated our lead requirements, but this was due mainly to the tanks and plates. We sort of expected this, and it was easily sorted. We dumped a bunch of lead on shore, and went about having our dive. We dive suits for squeeze, and wings for lift, and didn't find it all that big a deal. We worked through the Padi requirements for the cert dives on our own, and was pleasantly surprised how well it went. We inverted, did feet up recoveries, somersaults, etc... Maintaining neutral buoyancy was not an issue, and after a little while, felt very natural. The dive was about an hour long, and as such, with the shallow depth, we still had half full tanks. We used the same tanks for the 2nd dive, and was able to do a proper weight check at 250psi with a very slow controlled ascent from 20 ft at the end. This should well cover our weight requirements for a lightest case scenario. We had no issues whatsoever, and the suits performed and fit great (thanks seaskin).
3rd dive was just a fun evening shore dive with our local dive group. No skills or practice, just a nice swim around in our new suits. Suiting up is getting even easier with more practice, and the diving dry feels pretty natural already. My wife claims she feels about as perfectly neutral as she ever has, and already now much prefers the drysuit.
All in all, we found it quite easy to convert to diving dry, and sort of feel like we saved $800 on the cert cards. I was prepared to take the course if we struggled, but thankfully it is all going smoothly. We are lucky to have a pretty active local dive community, and the vast majority of the divers eventually go dry, so we have a vast experience pool to draw from. Time will tell, as we have some deeper dives planned soon, but I feel confident that if we take it slow and easy we'll be just fine.