I'm considering getting a hard case for my new Macbook, mostly considering the Speck See Thru Satin since I can't really find other good products, and was wondering if they scratch the aluminum on the macbook? I know people have said that hard cases have made it even worse from debris getting in between the outer Macbook casing and the hard case but I was wondering if there was something special, either about the new aluminum Macbooks or the See Thru satin, that made this not happen. Thanks~