I'm still riding a set of Conti Ultrasports that I originally put on my Cervelo P2C as a temporary backstop until my GP4000s came in the mail. I know they're slightly heavier, but honestly, the difference isn't big enough for me to get rid of those tires, and they also haven't flatted on me for the past few months. More than surprised with how well this cheap ($20 at the LBS!) tire works, even for racing guys like me.