I would say the best performance out of your cells will be with in the first 30 to 40 cycles. After that they are not as good as new but still good enough to race with week to week. I usually run my packs about 2 to 4 times every weekend and so far the new cells are holding up great. The older GP cells for me did not hold up very well they only lasted about 4 months of use....but it would be hard to find a matcher now that is still selling the older stuff. So any GP cells you get now are going to be very good and they seem to keep very well too.