I'm looking for a 27" TBD for my MacBook Air. I can get a refurbished from from the Apple Store for a pretty decent discount. Is it worth waiting for a couple months to see if they update it, or would it make more sense to buy the refurbished model now and save some money? Having a hard time making this decision as I could use it now, but I guess I can be patient if needed. Also, have there been any screen issues with the 27" TBD at all?