Who cares. It all cobblers. Nikon are better with noise and dynamic range because they use the Sony sensor. It only matters if you want to change brands or own a Nikon.
Its just one aspect of choosing a camera. Great cameras but erogonomically Nikons are a bloody nightmare for me so I would never buy one. And the 5D3 is good enough for me as is the 1DX.
Recently i was photographing alondside a guy using a D4. My 1DX was running off sequences of 12-14 frames perfectly in focus. His D4 wasnt even close. Does it make the 1DX a better camera. No, not really, but maybe better in this instance. Another time, another place maybe the D4 would come up trumps.
Too much emphasis on sensor quality and noise, as though its the holy grail of image quality.