I switched over to all NiMH a couple years ago. 1650mAh 9.6v Tx and 1450mHh receiver - but kept the 4.8v. If I need more - as in my 27% Ultimate, I add a second set and a combiner but keep to 4.8v. That gives longer flight time and I don't need the added torque as I used big enough servos to begin with. If I was starting from scratch I 'd probably go with more mAh, but I can charge the 1450 and 1650 with my existing chargers and fast with my Triton.