Thats the reason I did not move from my D90 to D600. Wanted a FF but with the D800 left AF problems and the D600 oil problems very happy I went with a D7100 instead. Was on the cusp of dumping everything Nikon and moving to a 5DIII and am still at a point if I have trouble with Nikon, real or perceived will move to Canon.
Excellence is an art won by training and habituation. We do not act rightly because we have virtue or excellence, but we rather have those because we have acted rightly. We are what we repeatedly do. Excellence, then, is not an act but a habit. - Nicomachean Ethics