Cycling Tips on his one-year experience with 404 Firecrest clinchers (read the comment at the end, not the initial review).
He and his teammates had a litany of problems with spokes, hubs, and rims, culminating in a blowout on a high-speed descent.
It should be pointed out that he's a big guy (probably up around the 80 kg mark), and an absolute watt monster when he's in the mood. But it's also very unusual for him to say something less than complimentary about equipment.
My conclusions from this are:
1) I'm sticking with tubs on carbon rims for now, even though they are a massive logistical PITA.
2) When I get a new set of race wheels made up, I'm getting them custom built with robust hubs.