Not really sure. Our AFM has some kind of playfield-wide protector/mylar over the new playfield, and no wear is observed at all. I'm not even sure if it is a mirco playfield, but it is new and here in the Netherlands it can't come from lots of other places.
Our MM playfield is new and looks great, aside from the huge amount of ball-dents everywhere. The wood used isn't too hard, but that seems to be normal. You only see them from a specific angle though.