I've always used a speck shell case on my previous laptops but thinking of not using one on my new MBA. How easy does the outside scratch? I'm usually pretty careful with my laptops and it mostly sits on the couch anyway. Should I stick with using a shell case, or go with nothing? I ordered the Kuzy case, but was pretty unimpressed with it so was planning to order the Speck. Edit: I know two people at work who have Airs and treat them like crap with no case and they are actually in pretty good shape. I think I just convinced myself to get a sleeve and no hard shell and I'll see how that goes.