I'm still running NIMH in 1/12. I picked up a nurse last month along with new race packs for this season. I haven't had it long enough to say much one way or the other, but I did notice that last year without the nurse, my packs seemed to go out of match by a lot... traying them before charging, one or two cells in a pack the lights would go out qyuick, while the others in the pack would take maybe half an hour or 45 minutes to get down to .9 on the tray...

Now with the nurse, the cells all seem to hit .9 in the tray within a few minutes of each other... This seems to me to indicate that the nurse is keeping the cells in similar condition... no packs with one or two weak cells so far...