I recently ordered a D600 kit from Adorama, and received the camera and lens last week (parts of the kit are still on back order). Thus far I have only used the kit lens.
My camera came with a couple of strange defects.
First, it would not autofocus at all in Live View mode - it just hunted back and forth but could never come close to focusing. If I pushed the shutter button hard enough to take a shot it would do so, but would choose a focus seemingly at random, and none of the shots was even close to being in focus.
Second, it would not shoot continuously in either continuous shutter mode - I would get only one shot per push of the shutter button.
Because of these two obvious flaws I have sent the camera back, and am hoping for better luck on the second go-round. I am just curious if anyone has experienced similar issues. I will update once I get the replacement camera, which I hope will live up to its potential!