[JesseK]

Calibration of motor controllers is a pretty standard practice in RC (especially in the quad rotor world). If the controllers aren't calibrated, the motors will not be in sync (i.e. receive the same power input) -- which could be an issue for motors that are mechanically linked. In quadrotors, the motors are linked via software PID for stability purposes, meaning uncalibrated motor controllers will cause a quadrotor to crash almost immediately.