I'm returning a Macbook Air I purchased last week at an Apple Store (not because I don't like it, I just need a bit more screen real estate) and I want to make sure I put it in an acceptable state. I'd like to remove all the data that I've put on it in the last week but I don't want to go overboard.
Should I format the drive and return it with no OS? Format and reinstall the OS? Leave it as-is and trust Apple refurb to not look at my data?