I have Velocity Aeroheads as does my DH. I can only echo what others have said in terms of rebuilding them. I have Sapim double butted on my wheels. Your hubs may need new bearings, but my guess is that the Ultegra hubs are fairly easy to service.

I would argue that you don't need to go with a 32 spoke count; you just need to find a good wheel builder. My own wheels are paired with White Industries hubs and are built up 24 1x front, 28 2x rear nondriveside, 3x driveside. I weigh 120-125 pounds, and I ride plenty of crappy roads without any problems. I love my wheels.