I don't know about the technical numbers but the EOS-1D X is my favorite current camera to shoot with. My reasons for this go beyond the numbers and extend to how they have rethought the control layout. The one thing I do not like about it is that it is hard to see into the corners of the frame - eye relief.
As 24x36mm format DSLRs are concerned, the D800 can't be beat for sheer technical considerations image quality but technical camera qualities are far from the end all and be all of what I look for in a camera. If you primarily shoot landscapes, still lifes, or set up portraits then the things that the D800 excels at come to the forefront. but as a "put on my shoulder and walk around camera" I really am quite fond of the 1D X.
The D800 lacks any kind of image quality for me because my lenses don't fit on it.
I've never been on DXO site, I have no interest in lab rat numbers.
A camera has to work for me with what I shoot and how I do it. No doubt the figures will contradict me but I think the X has far more shadow depth than the 1DsIII I had. I also think there is more in the colours. The AA filter is very weak. Right now easily the best all round camera I've ever had. 12 fps great for doing panos in a spot turning helicopter.
I'm liking it more and more. The 1DsIII was a disappointment from the start, getting it to focus was a challenge sometimes and I never felt the DR was very good and I could hit the buffer too easily when shooting a sequence. The X's high iso is a revelation, I've not used it in anger but I tried 12,800 in a dimly evenly lit room and it was very good. The real test for high iso is in scenes with uneven lighting, that bit between detail and black is what decides it for me in the shooting conditions I need high iso. And it upscales very nicely, I think the weak AA helps with upscaling.
Great camera the X.
It's all X files for me these days, no mystery as to why.