I've found that the majority of flats I get are on the back tire, also that the back tire wears much faster. I've also found that once it starts going, it goes fast - by that I mean that the first roughly 5500 miles were almost flat free, the last 500 miles ramped up to about as bad as I've had with any tire. Partly I think it was just old, worn and easier to puncture. Partly I think I should have booted some small (< 2mm) punctures better, and they just allowed stuff to get through to the tube or let the tube push out enough to puncture. Almost entirely urban riding, rough roads with lots of debris. The tires were Michelin Transworld City 26 x 1.5, $20 each, until the last 500miles or so I was very happy with them.