Have used both Specialized Armadillos and Performance Pro Kevlar belted tires for the past five years and have had two flats. One was a rock cut on the unbelted sidewall which I repaired with a dollar bill to get home and the other was a pinch flat from a larger stone (like the one that cut the sidewall). Both were last year along the same section of road where the was a bunch of spilled riprap rock. I no longer ride that road. In over 8K miles I have had these two flats. Nothing like kevlar belted tires for the road.