On-One is starting to push out XC and DH carbon frames, and I'm a bit tempted by that 456 monster.
Carbon though...I've had a carbon frame in the past and really enjoyed it's characteristics, bud it lost bits of the 'cosmetic' layer quite quickly, especially around the seat stays, and that was on fairly standard XC stuff. I shelved it after that and went back to alloy.
But carbon keeps gaining ground, so what's the real world experience like for others out there? How bad has it got, and how quickly? Or how well has it survived?