This is exactly correct. Low 10s of kHz is quite functional for machines moving in human space / speed. If one is trying to do some assembly line (max # of op

This is exactly correct. Low 10s of kHz is quite functional for machines moving in human space / speed. If one is trying to do some assembly line (max # of operations per second), the power requirements alone get hard to manage. And then you're managing back EMF, eddy currents, heck, air resistance! My rule: have dedicated low-level hw provide smooth PID response, mostly on the P term; and have a higher-level control produce the setpoint. Faster response means less need to rely on I or D terms as much (just because delta-T is so relatively small).