...
Until those companies start actively heat testing their epoxies and posting the results, I'd not recommend them for somebody that lives in the mountains.
There has not yet been a Zipp firecrest meltdown.
Yeah, this part is important to me, Zipp is claiming they fixed the heat buildup problem, whereas if you look at the November site they make you sign an acknowledgement that the warranty will be void if you use them on dirt, centuries, events requiring a downhill neutral rollout... pretty much if you use the brakes you're out of warranty. Boyd reminds you to alternate brakes instead of riding them. Zipp says they've solved the problem.
I guess I just drank the Zipp coolaid, when it comes down to it.