My battery pack went through about 25 charge/discharge cycle since near the end of March this year. I charge them once a week because I use them for 2.5-2.75 hours a week. The first 20 cycle, I were getting at least 2.5 hrs before recharging. The last 5 cycle, I get less than 1.5 hours of run time.

I doubt the new battery will be any better than the old one unless they used better 18650 cell so that they are better balanced and less mismatch in the 2S2P hookup, but base on the price I kinda doubt that and issue such as diminishing run time from the pack going bad will be a common thing.