Thanx frankt ... I was a bit skeptical in the begining as well. I have worn this just about eveyday since I got it and I can tell you, the finish is indeed, tough. Unless you were to get a really big, deep scratch in the case, the finish seems to "hide" any small imperfection ... certainly better than my polished AND brushed examples do over time.
As for the darkening, I would assume that unless you took a toothbrush and soap or something to it, "stuff" would collect in the matte finish giving it a sort of patina. I am not saying this has happenened to mine yet, just that I am told that it will.