The main thing is some racing you will need to run sensored motors.Unless you run strickly mod. The mamba is not designed for sensored but the Speedpassion will run both. If racing from a standing start the mamba will kinda studder and sometimes it can cause a problem on starts. I have some low turn delta wound motors and also run some 10.5 and 13.5 sensored motors and It's nice to just plug in whatever you want and the speedo runs them all.