D600 dust accumulation time-lapse

Now that does not prove anything at all. One dust mote which was somewhere in the body moved around over time and finally settled on the sensor - that can happen with any camera.

(And it has actually happened to me, with an X-Pro1. I just activated the self cleaning function and it was gone again.)

No offense, but this complete inability to differentiate between significant and insignificant observations shown by many discussion participants is a major part of the problem. There might actually be _something_ wrong with the camera, but there us simply too much noise for anyone to do a serious analysis. And I could imagine Nikon has exactly the same problem...