Just purchased it after i had the D800, and in many aspects it can be considered as a pro grade camera (built quality, image quality..). However I must admit that this camera is not as PRO as its direct pairs. mostly due to the lack of personal customisation. Also it suffers of stupid things which could be fixed by firmware update. always a screen turned on sucking battery, little lag when you travel into the menu and/or change aperture, top screen lagging or when zoom images. tad less finition about the buttons. when you change iso setting it takes too much place on screens removing all other informations and you don't see the speed increasing... such things, really stupid.
I would not change, but in one word: not mature.