I've had more AMD systems shit out on me then Intel systems. and i have never overclocked a processor. And that's just from my own personal computing expirence. I've owned three webservers... 1 AMD-based that died within months, and two intel sytems that haven't quit yet.
My current PC is a AMD system that i have not had any problems with, but from my personal track record, intel's chips are more reliable. AMD's are fine for personal use, but a webserver is something i'd rather not chance.