I will be unloading a small lathe tomorrow morning for my home shop. It currently has a 240/480 motor on it. I am also getting a small VFD on a drill press, too. I need to research which will be more efficient on the lathe, since it gets run for long periods, use the VFD or get a 110V motor as I rarely reverse the lathe.
The VFD will give you an almost instant brake for an emergency stop, and it will also ramp up and down to speed slowly. Remember there is a lot of mass in the gear train to bring to a stop and reverse, so you don't want things happening too fast.
The VFD is very nice for making the machine run very slow for operations like threading.