Full carbon rims have come a long way in terms of braking performance. I’ve just started riding 2011 Hed Stingers on the road, in the past having generally reserved similar wheels for track use because of the poor brake feel and also the mandatory tubular tires. The new wheel’s braking felt surprisingly smooth, not shuddering and uneven. I have yet to ride them in the rain, but I was feeling at ease in the dry after one ride. I’m using Swisstop yellow pads, and I felt satisfied with their performance and how they treated the rim surface. For brake pads, they seemed shockingly expensive to me at first, but hell the wheels retail for $2200 for the pair so I guess that’s just part of the game.
One annoying thing about the current generation of toroid-shaped rims is that the brake calipers on the market currently were clearly optimized for 19-20mm wide rims as opposed to 23mm+ of newer Hed or Zipp. As a result, you have to run those calipers, like this SRAM Red, at full open, and perhaps the caliper doesn’t contribute any spring resistance back to the lever to keep the blade from rattling.