Jack, I do agree the endless dialog about DR in Canon vs. Nikon and therefore all matters are settled Nikon wins, is a somewhat over the top. So I AM with you
And I agree that at ISO 3200 the 7DII and 810 are neck and neck on DR so would agree that the 7DII with it's superior focus speed and fps (+/- on the crop sensor, depends on what you like) makes it very attractive.
But respectfully the argument spits the bit against the D4. The D4 was MADE for this. DR is a good ~1.5 stops deeper. D4s holds on even longer. The D-series is just too good at this
Of course we are back to the never-ending DR issue again and how much it really matters to a finished and pleasing product. But I fear that will never be completely resolved for people as myself who look at the camera-image as a complex continuum, not just a specification no matter how honest its derivation may be as in this case.
Cheers
Interesting, while Bernard keeps extolling the virtues of the D810, ignoring the strength of the Canon 7D II for wildlife photography, with its excellent high ISO capability, peerless AF + high FPS, the reviewer of this Sigma lens (on Nikon's behalf, mind you) says,
"10) This lens is a natural fit for the D4s. The lack of wide apertures plus the focal lengths mean that you will likely be shooting with higher ISOs than the D810 can comfortably offer, in my experience, unless you have the best light or slowest subjects. Plus when shooting mobile subjects at such long lengths, a higher frame rate is extremely useful."
All of which are strengths of the 7D II, which pretty much either matches or eclipses the D4 in these areas too ... for 1/3rd the price ...
Jack