The service form Nikon Europe is definetely better than Canon Europe CPS.
I had the change to test the new D4 and the D800E for some weeks.
The D4 is approximately on the same level like the 1D X. The 5D Mark III is a good deal worse in JPG like the D800E.
If I compare the D800E against the 1 Ds Mark III in landscapes I mzs say that the pictures of the 1 Ds Mark III are sharper and the colors are more even.
There will be a big megapixel camera from Canon in the next month.