I can't afford these wheels, and, unless you race, you probably won't want to spring for a pair, either. But people in this forum talk about wheels a lot, and this is a pretty neat set. C&A has come up with some rules of thumb, like if a wheel doesn't have 32+ spokes, it won't last the rest of the day ... so, if nothing else, these might be interesting. I mean, here's a wheel with 12 spokes that's rated for 700 pounds!
LBS lent me a pair to play with for the weekend. My bike weighed 15.5 pounds (ready to ride) with these wheels...! Climbing was a bit easier, and so was sprinting, but the weight was most noticeable when I'd carry the bike up and down the stairs between my apartment and the road. The aerodynamics (vs my wheels) felt like a more profound change than the weight.
Going back to my wheels was a bummer after a long climbing ride on these. At least now I grok what kinds of differences good wheels can make, compared to decent ones.
^ Forgive the lousy camera phone quality, and the slightly odd camera angle. Here's my bike with the crazy wheels, at a park called Forrest's View. ( I like renaming parts of my rides. You should see Mount Terror. )