>How a DX crop photo taken with a D600 would compare to a >native DX taken with D90/D7000? at 10.5MP I suspect it is at >least at par with my D90, right?
I suspect the same. But if you get the D600 and start shooting with it, I am sure you will soon discover the advantages of the larger sensor and won't be using the crop mode for long. So this question may not be very important in the end.