Battery voltage is one thing to consider about the 2.4 Spektrum systems....I'm not sure if this applies to the Fasst systems tho. It may but I don't know for sure. I have seen a few birds go down in flight with 2.4 systems due to low voltage to the RX while if it were a Standard 72mhz system it most likely would have made the rest of the flight and land safely. The 2.4 systems goes into a reboot mode at low voltage (or something like it) and I personally feel that 2.4 rx's should be ran on 6V's to lesson the possability of voltage reboot. At least you will be further away from the min voltage to start....