I received the refurbished Air a few days ago, and it really is a beauty. Because of all the comments here, transferring files from my old MBP via Time Machine was a snap, and other than figuring out how Yosemite works, it's been a dream. My biggest challenge has been trying to decide upon a light but very protective case/sleeve for it, given the plethora of choices out there. Yesterday, I took it off power and started using it. Chrome was open, but because there was no wifi, I wasn't using it, a little bit of book reading via Preview and about 20 minutes of classwork through a downloaded quicktime mpeg4. The battery was dropping faster than I thought, but altogether, this was an hour max. I came back home and decided to see how the battery worked on regular tasks, so it was just internet browsing and Preview. No Quicktime, no iTunes, home wifi. In five hours, the battery went from 100-14 percent, which I found surprising. I called up Apple and he suggested that I always stay on battery life, let it cycle down, not leave it on AC power when it's fully charged; also helped me set up an appt at the Genius Bar for tomorrow (which sadly means I'll be carrying my unprotected laptop with me all day! I'll be swaddling it in a towel!) I know the answer is to see what the Genius Bar says, and of course, they'll fix whatever's wrong, but I'd love to hear any thoughts you might have. Am I overthinking it? Is this typical? And because I can't say it enough, what a pretty, pretty machine!