RE: 2.4 Receiver Batteries
Myself and many others in my club have gone to two cell LiPos, LithIons, or A123 cells instead of NiCad and NiMh. They charge faster and they hold their charge much longer. They are lighter. They do not False Peak the charger.
I have never experienced any problems with these types of cells. I do disconnect them from the Switch Harness, at the end of each flying day, just to avoid an accidental Switch On. There are more HV servos available now, so running without a Voltage Regulator becomes more common.
I use them in all my Transmitters, as well.
With chargers like the FMA 10S and the PowerLab 8, you can charge at 3S, 4S, 5S, and 6S, depending upon what Power Supply you use and the batteries you choose.
There is no problem with Current Draw, either.
I believe that with NiMh, you need to choose cells that have low Impedance in order to handle the higher Current Draw.