Originally Posted by numberSix

and...
IMO, flat on a carbon tubular, and the rim is mostly protected by the glued tire and the flat-ish tire bed shape.
Flat on a carbon clincher while hauling ass, I don't see how the sidewalls will survive unscathed.

All the fast guys I ride with are on carbon tubulars.
All the enthusiast cyclists are on carbon clinchers.
All the -wide- cyclists (like myself) are on alloy, and just pedalling harder.