Just FYI...a couple of years ago I had started a thread about tires that could be used for both training and racing. The two tires most mentioned were the Michelin Krylion (then in the process of being replaced by the Pro4 Endurance) and the Conti GP4000S. Since I was coincidentally already running the Krylions, I stayed with them and replaced them with the Pro4 Endurance when they wore out at the end of last January.

I'm about to replace the P4Es on my race/training wheels with the barely ridden ones on my spare wheels. They've got ~3200 miles on them, and I'm replacing them due to the rear tire being squared off; the rear still has a good bit of rubber on it, and those tires will go on my spare wheels. No flats, and that includes using them for Rouge-Roubaix with its 20+ miles of gravel plus all the lousy roads I've ridden on since. My average weight was ~185 over that time period. The tires are the 700x25 version, and measure 27mm wide on my Open Pros; I've read that they measure 28mm on 23mm rims. I've used them on my CAAD9, Look 585, and Specialized Allez with no clearance problems.