The motors just a normal motor. Is it the belts and or the controller everyone hates so much, or cost of boards/parts? Now that I've been forced to have a bunch on my route, they really ain't that bad, and otis will sell you all parts. The biggest drawback to a mod I see is belt monitoring. You either need to make their pulse unit communicate with a new controller or make your own pulse unit from the ground up. Unless someone's getting crazy and replacing sheaves and everything to go to ropes like an ecospace. But at that point why not just install a whole new elevator?