with a better charger you can charge at higher rates, with my lrp i charge at 5.5 amps, and the before my race i peak them up at 6.5/7 amps. people may say thats to high and may well shorten the life of the cells but it works for me and some of the guys that i race with, but anyway most good chargers go up to 7amps so you have lots of charging options!!
i agree with trf racer, if lrp put a 30 amp discharge and a motor rpm function on it, it would be the best charger out there
any way these are my thuoghts hope they help you a little,