I have a KitchenAid 11-cup processor. I've had it since about 2002, and I use it regularly (minimum once a week, most often more frequently). I've never had a problem with it at all. I've used it so much that the clear plastic bowl isn't so clear anymore (lots of fine scratches), but I can easily buy a placement bowl on-line if I wanted to.
If this one stopped working, I'd go out an buy one just like it. Another KitchenAid.