If no discussion of C vs N then I suggest you reword your original post.
You opened up the topic in your first line by saying Canon needs a chip to compete. Either it was a flame or a poor choice of words.
I think it unlikely that we see a 5d III replacement this year, the body hasn't been out long enough.
I know that the Sony chips(Nikon) are better in dynamic range and especially the gradation in the middle tones. This is from comparing my Mark II and Mark III files with Nikons D600, D7100, D3x and a few D800s. This comparison was done on jobs allowing direct evaluation. I have also compared, in studio, the Leaf Aptus 45, Imacon's older chip, 5D Mark II and Mark III. For most usages, the Canons were great. Again, the middle tone gradation was the only issue. Both the medium format chips have much larger pixels. Thus the tonal breaks were very smooth compared to the Canon's.
But back to the reason(s) for my question. AF is a major advantage of the Mark III as is its better high ISO performance. But at ISO 100-320, I can not differentiate between the cameras. So is a 3300 dollar price justifiable if only for AF and high ISO performance? Kind of a rhetorical question.