I've had a set of Ceramic Mavic open pros that I used on my road bike for a few years. I recently down graded them to my cross bike. They have changed my cross bike. No matter what the conditions, my brakes work, and work great. I did a local MTB trail yesterday, and due to a little rain, I was going through big puddles, and my brakes still had tons of bite.
If anyone is looking at getting new cross wheels, pick up some ceramic Mavic open pros for clinchers or Ceramics Reflex for Tubulars.