A brush motor controller and what are the advantages and disadvantages of brushless motor controller?

there are motor controller: the advantages: cheap, simple technical weakness: the conversion efficiency is low, the noise is relatively large, the speed is not high, short life brushless motor controller: advantages: high speed, large output torque, long life faults: technical requirement is high, the cost is expensive. A brush motor controller adopts mechanical commutation, poles, coil rotation. Motor controller is working, coil and the commutator rotating, magnetic steel and carbon brush don't turn, is the direction of the coil current changes with the motor controller phase switcher and a brush.