I did ~6,500 miles on 700x25 conti gatorskins in 2011. My last rear tire lasted me just over 4,000 miles when I got my first flat - a nasty gash that meant I had to repalce the tire. I probably could have gotten another 1,000 miles out of that tire if it were not for the gash. My last front tire lasted over 12,000 miles (flat free!) when I replaced it. That tire would have gone further, but it was two years old and looking a little ragged, so I replaced it just because. IMHO Gatorskins offer a decent balance between rolling resistance, flat resistance and tire life.