Just to be clear: The Revo doesn't need a servo to shift, but if the 2 speed is left intact, you can't have motor brake/reverse. The emaxx tranny is totally different and does need a shifting servo for two speed, but you have motor brake/reverse in both speeds.
well the exv esc can only handle 12 cells but that is fine for me for now and I will be using the e-maxx tranny is it possible to lock it into 2nd gear? or should I keep the 1st and 2nd gear with the shift servo?