I've got a pair of Ultremo R.1, and I really do think they're the least puncture resistant tires I've ever used. On the other hand, I expected them to be -- the other tires I'm comparing them to are all heavier commuter tires. I got two flats on the rear tire in about 600 miles, both times picking up junk in suburban bike lanes. My theory is that the high thread count grabs and holds pokey bits more often than cheaper tires would. IMO, the ride of the Ultremos is worth the extra flats in the right circumstances.