Nikon d800 in DX mode and image quality

It seems to me that the IQ on a pixel basis should be the same in DX as in FX (noise, DR & so on). You are using the same pixels and processing after all. The difference should appear in the available detail for a given size print and would be mostly noticeable in larger prints I suspect, not that you couldn't pix peep and find a difference in a smaller print.

I would expect the noise/high ISO performance to be superior to that of the D7000 because of the newer and more capable ASIC chips in the D800. Just how much better would best be answered by actual comparison.

I have seen larger prints of images captured with the D800 in FX mode and the detail was quite good. I doubt any DX image would be quite as detailed without some manipulation, although some people might disagree.