I run the carbons on my DH bike with 203 rotors, I'm happy with them, the only gripe I have is that when the bike is left for a week or 2 they become spongy but this soon goes away with a few lever flicks before the first decent.
yeah that happens with mine, too. weird. i have xt brakes on my other bikes and marginally prefer them, but probably partly due to having xt on the bike i ride every day so am much more used to the feel on those.
generally they're very good – nice feel and very good power with 185mm rotors.