I would add to this that very rarely is a shop (especially midas) going to knock off the back drums to check your shoes. I used to work at a tire shop and I believe we rarely checked them. Usually the only reason why we WOULD check them was because our mechanics worked on commision. Sometimes getting those drums off required hitting with a hammer. Doesn't hurt it (moderation people). I would also like to know about the PowerSlot rotors as I plan on upgrading to these all the way around.