I used the GP 3000's and then the GP4000 for the last 5 years or so. I usually by 4-6 at a time, I did have some sidewall issues @ 4 years ago, none since. I run the 25's and get over 4,000 mi before I rotate them onto the back up bike. I just bought a pair of 28's for the tandem we just purchased. The roll and wear well. I'm 185, run 95 r 70 f on wide road rimes( Boyd), I run 110r 90 f on Ultegra rims (1st gen). I've have been very happy with them.