I just looked through my logfiles and i'm now at cycle 75 with my Sony cells. Still charging back 2200mAh as 9s2p. When i started using them as 4s4p i charged 4400mAh back. So no noticeable capacity drop. I guess they will have a very long life in my setup. Sikestone: With a driving time of 25min they will last even longer with your setup. I'm discharging mine now in 8 minutes. In my buggy they lasted for up 13 minutes.
@lutach
Guess i use them up to their full potential then (didn't notice the 60A fuse). I red somewhere that each cell has some kind of integrated fuse which will render those cells useless when you overwork them. If you push them too hard the fuse will trigger and the cell is at 0V ... this is not reversible.
Edit: found some pics of those cells open ->
link