D600 - Dust Accumulation...
I received my D600 two days after its release (ser. #3007970.) It now has a little over 4000 exposures and probably 200 to 300 lens changes. There's not even one speck of dust on the sensor. I checked it yesterday with the mirror up, a high intensity lamp, and a magnifying glass. Remarkable handling and splendid images. - The camera has already paid for itself several times over!