I recently got my Hayes HFX-9 Cabon hydros and they are amazing. I rode 50 miles yesterday, quite often through foot-deep mud and they were great. There was a bit of rubbing at the end of the ride but I was told that it was normal for disc brakes (I ended up taking out the pads and pushing the pistons back manually and now they run smoother than before). After that I rode my friend's stumpy with Avid rims brakes and flew past the turn is was trying to make...HUGE DIFFERENCE. My vote goes to the hydros!