i run a Mamba Max in my X10 & its never cogged stuttered or anything bad, i've not even had to shorten any wires or hardwire to remove any connectors
tbh i found the new firmware a bit of a dissapointment as it seemed to lose punch, it seems like you have to let it wind up now where it was really aggressive and explosive before!
it will probably be better to drive in the long run but it was kinda more fun before
i also had to make a little platform for the speedo in the centre of the car which is easily done from leftovers from other kits