I'll concede that I think the D800 has the better sensor. I don't see this as showing how bad the 5D mkIII is, I see it as a testament to just how good the D800 is. Hats off to Nikon.
However, I'd rather be out shooting and enjoying my decision, Canon or Nikon, than sitting on internet forums whining about it. I have a 5D mkIII and I like it. It's sensor may not be as good as the D800, but I'm ok with that because the 5d mkIII delivers for me.