I got my MBA 2011 as soon as they updated it around the lion launch. I take very good care of it and clean it weekly. Today the MBA fell three ft and now has a small den't on the top case. At least the case does not break apart like the old white macbook I got when they first came out. Question--Do the hard thin cases that clip on the MBA's and MBP's really work. Would you suggesting buying one. I have been using a book book case more as a leave or pouch when traveling.