"After seeing Nikon's quality control problems with the D800, I'd advise waiting at least 6-8 months to buy a D600. There's no sense in being on the bleeding edge of technology if you have issues with the equipment."
The D600 is not nearly as "bleeding edge" as the D800, e.g. 24 vs 35Mp. It's also made in a different factory, Thailand vs. Japan.
Gary in SE Michigan, USA. Nikonians membership - My most important photographic investment, after the camera. D4, D810, D300 (720nm IR conversion), D90, F6, FM3a (black), FM2n (chrome) YashicaMat 124, Graflex Speed Graphic 4x5 My Nikonians Gallery & Our Chapter Gallery