You probably wouldn't feel that much performance gain, but run time would increase massively. The cut off prevents the lipos from dropping below 0.3v per cell, but make sure it is a lipo safety cutoff like this
http://www.jemodels.com/electric-mod...FczHtAodJ2YAaQ
To charge lipos, almost all are rated at 1c. That means for a 5000mah battery = 5.0a, 6100mah = 6.1a.