Bought a refurb, was fine for 6 months till the airport card went, from then in was a comedy of errors at the apple authorised repair centre.
Had Airport card, logic board and display replaced (20 days repair), came back and wasn't charging. Off again and battery and DC in board was replaced (17 days repair), thremal sensors on logic board had gone and KB backlight didn't work.
Finally had enough and demanded a replacement, now this is worth bearing in mind where buying a refurb is concerned;
Apple will only replace a refurb if the have the SAME model in stock, otherwise it's a refund. The warranty is not exactly the same as a new one as they won't replace for the next model up if the one you have isn't available.