I had more flats when I rode a MTB with knobbies, and my hybrid with 35's. I went to 25's with extra kevlar reinforcement, and I have averaged one road flat a year, not including my Schrader valve stem fatigue blow outs, but I remedied that by converting to Presta valves. I've ran over some serious debris, making some loud popping noises, and I was relieved to hear no hissing sounds and to have a still fully pressured tire at the end of the commute. Just looking at all the serious gashes in my tire, makes me think that a lesser quality tire would have left me on the side of the road many more times making tube repairs.