I think 1500 is an OK level. But some of us tone the amps down a bit for longevity. Want a reliable fast mid drive? Think Lightening Rods. We sell dozens of parts orders daily, and few if any nylon gears. I’ve had spares for every one of my 6 BBSxx motors. 01, 02, and HD’s. They are all still in my parts box. One article by an abusive user has spread a false urban legend.
MM G320.1000 or what is popularly known as the "BBSHD" is rated at 750/1,000 watts (I guess depending on the choice of controller).
MM G510.750/1000 or what is popularly known as the "Max Ultra" is also rated at 750/1,000 watts.
Yet many of these motors survive continuous abuses from hot rodding, producing 2-5 times the original power.