If you're in the mountains a lot the carbon rims simply don't match the braking performance of an alloy rim. For this reason I ride the Shimano DA C24 wheels. They are plenty light enough, have no weight limit and ride superbly. Their bearing structure is a model of precision and they never fail. However, those deep dish carbon wheels are alluring. If you ride the flat mostly, the deeper dish rims should have an advantage when you're riding an average speed in the lower to mid twenties and above. I would focus on wheels that have seen more use and you can get feedback on. The boutique wheels like AX Lighteness.....pass on them. They tend to be more experimental in my opinion. If you're going to pick up a set of carbons for their light weight, then go ahead and get the tubulars because clincher carbons don't provide enough advantage over the DA C24 wheels to warrant their purchase.

The Mad Fibers are interesting and I know a couple people that have them. They make a whirring noise but are suitably lightweight and seem to hold up ok. They are not the stiffest wheel in the house but this doesn't bother me (it might bother some though). The RZR wheels are quite expensive and I don't know much about them. You reach a point when I think its better to go ahead and look at Lightweight wheels . The run about $5k but there are plenty on the road and their reliability and performance are extremely good. And they can be ridden as everyday wheels. They are held in high esteem on the Weight Weenie forum - and that's a good forum for wheel feedback so consider posting your question there (or search their archives).