Thanks for the reply mate.Numbers are great but they dont tell you everything.Both the d810 and d750 beat the d4/s and 1dx according to numbers on this site.Canon 1D X vs Nikon D4s - Our Analysis
Canon 1D X vs Nikon D800 - Our Analysis
take your choice. Nikon wins both
Or this Nikon D4 vs D810 - Our Analysis
But these cameras are over twice as expensive as a d810 and around 3 times the price of a d750.Something doesnt add up here for me.I doubt its just the FPS you're getting,im sure the higher iso capabilities of the pro body is accounted for in the price.But there must be more to it than that.
The 5d3 has the same AF system ON PAPER as the 1dx.But in reality the 1dxs system is better(from what i've read).
ON PAPER the d810 and d4s has the same AF system,id be surprised(and bummed if i bought one) if the d4s doesnt have a better af system and if nikon doesn't have their flagship camera having the top AF system(these are sports/wildlife/pap cameras...stuff thats moving basically) then it may not be worth the cost.
Id bet the d4s has the best dslr low light performance currently and that includes the 1dx.But i feel the canon may be ahead on af....haven't tried either though...just going on what i've read.