One of my grinders, like my Delta mitre saw, employs electric braking by dumping the power generated by the run windings into some kind of resistance. Really slows down the "coast to stop" time. But admittedly a truck disc brake would stop even faster. ( was gonna say "would slow faster" but that seemed a bit contradictory.)
Busy Bee 12-36 lathe, Busy Bee Mill drill, Busy Bee 4x6 bandsaw, Homemade 9x17 bandsaw, Ad infinitum.