You also have hasselblad? Would be nice to have it compared in terms of skin tones, also at low iso in studio.
Its still half price of them(h3dii-22 is available at moderate price now though) and would be more versatile.
I used to have an H3Dii-39ms but now I have traded it in for a PhaseOne IQ180. The H3Dii-39ms took some very nice images, and obviously has a lot more resolution then the D4, but as DxO mark says the D4 is higher then any of the Hasselblad's that they have tested in their sensor scores and I actually largely agree with this. The H3Dii-39ms took some great images, but OOC I think the D4 is just as meaty in this regard. However, I do not agree with its sensor being just below the IQ180's. I believe that the IQ180 absolutely blows it out of the water any day of the week.
I mean, this is straight OOC of the PhaseOne IQ180:
http://www.flickr.com/photos/brianhirschfeldphotography/6350486836/in/set-72157628023702699This is actually the first picture that I took with my Hasselblad H3Dii-39ms when I first got it. As you can see here it is wonderful and subtle in the way that it renders tones and colors.
http://www.flickr.com/photos/brianhirschfeldphotography/4710430972/in/set-72157627419431490And this is the Nikon D4
http://www.flickr.com/photos/brianhirschfeldphotography/6884521058/in/set-72157629704678057/Although the IQ180 image is not as comparable in terms of composition, lighting and subject, I think it clearly shows off the amazing straight OOC capabilities of the camera.
The Hasselblad preformed amazing at low ISO's 50 / 100 / 200 but even at the 200 end and certainly above in the 400 and 800 ranges (I believe 800 was/is its top) there was significant noise to the point that the files were useless unless for some reason you desired this aesthetic. The IQ180 heads all the way down to ISO 35 and does amazing frankly at all ISO's, so does the Leica S2 (You can see my flickr gallery of an ISO series of a jaguar wheel). I don't think the D4 has the resolution to be a studio camera. Obviously, I would opt for medium format digital, but I would think the D3x and the D800 have a serious edge simply because of their resolution for studio.
Of course its more versatile in just about every way, except cropping but they have different functions.