I have CXP33's on Ultegra hubs. 28 spokes front, 32 rear, DT Revolution spokes and DT Competition (heavier) on the drive side. Front radial, 2x 3x rear. GP 4000s tyres, and the thinnest conti innertubes. They are awesome wheels. REALLY stiff, not overweight (1700g ish) and faster than anything else I own. I borrowed some Zipps once, they were faster! But really, I recommend these rims strongly to you. They also handle extremely well, better by far than any factory wheel I've used.

The only weakness, if such it be, is that these are racing rims, and milled quite thin on the brake surface to save weight. If you plan using these in the rain a lot, and use your back brake lots, you may need a new rim after a year or so. If these are just for training then, use the training version of this rim, the CXP22. But if you are anything like me you won't have any trouble with the rear rim wearing out- can't recall the last time I put new pads in the rear brake even...