I don't own a pair of them, yet. But I've been wondering the same things. I'm considering them because the rim depth is only 44mm deep, which I think would be better in winds at Kona, and they are said to be as aero as a Zipp 404 by John Cobb on the Bicyclesports forum. I have heard they might be a little flexy for a bigger riders 180+ riding in american style crits. I haven't heard anything about durability of the rims or how good the hubs are.