Used it to replace the 400W clutch motor for a 1974 vintage Brother-DB2-B755 Industrial Sewing Machine. Installing the new servo motor was pretty straight-forward. Dialled in a max speed of 1200 RPM and it works like a dream. Was lucky that it worked with the existing drive-belt, so didn't need to buy a smaller or larger one (I had been warned about this).
What I found annoying, however, was the included needle position gizmo. No instructions on how to install or use. Looking at YouTube videos showed slightly different units and machines, so it's anyone's guess how this thing works. eg. Do you just use it to configure the controller, or do you have to leave it on all the time? If so, then how do you stop it from spinning around when the machine is operating.
That aside, love the motor. Dead silent when not running and – so far – works better than the original motor =)