The reason there are PowerBalls and PowerCones is because a round ball doesn't go in to a corner well. The cone will go into a 90º corner and a ball won't. The tools come in different sizes and shapes because wheel designs mean not all can be polished efficiently with one size.
A real advantage of our design is the individual fingers will do a better job of going around edges and corner than a solid shape.
The foam is very durable - as long as you read the directions. You don't need to run a drill at 1,500 rpm to get a good finish - 300 or so is more than adequate. The damage we've seen to PowerBalls and PowerCones is almost always from one of 4 things:
1) running the drill too fast
2) running it up against a sharp edge at speed
3) failing to clean the tool after use and storing it dirty/wet
4) forcing the tool, at high speed, into too small of an opening
And remember - the PowerBall and PowerBall Mini are reversible. You can take them apart and reverse the element, getting a new surface to work with. No other polishing tool does that.
The hardware between our tools is interchangeable, so you can use our sleeved extension with any of our tools.
The market for these types of polishing tools was about 294,000 pieces in 2011. We sold 265,000 of them. I have one of the original prototypes from 8 years ago that I still use, and it works fine. If anything, the PowerBall is overbuilt and they last longer than we wish they would.