I've read several good posts and write-ups concerning the cupped inserts. I'm sure this question has been put forth, so my apologies in advance. Why not just replace them? from what I understand they do not come level so they have to be sanded to be level, but it seems like replacing them would be a solution with far better results? Once again, my apologies if I've misunderstood or simply missed the explanation concerning why correcting them is better than replacing them.