my porter cable works fine but i only use it for light compounding and finishing, being a DA i wouldnt try to use it to correct severe paint damage because thats not the intended purpose for a DA, theyre meant to produce a better final gloss than what can be achieved with a rotary, so if youre using the pc for a lot of compounding,(im assuming you would be using more downward pressure), then the spindle is under more stress and will wear out and fail quicker, my next buffer will more than likely be the makita bo6040