I'm also reading the graph of ISO, SNR 18%.
On Print, comparing photo to photo, the D800 and 5D3 are almost exactly equal, both above the 5D2.
Click image for larger version.  Name: 5D3print.jpg  Views: 51  Size: 91.1 KB  ID: 937

On Screen, comparing pixel to pixel, 5D3 beats 5D2 beats D800.
Click image for larger version.  Name: 5D3screen.jpg  Views: 56  Size: 101.6 KB  ID: 938

How does the D800 score 2800 and 5D3 score 2200? Maybe only 1/3 - 1/2 stop, but I call shenanigans on DxO.