IQ wise, the D810 isn't getting touched by an IPhone, unless you want to take all of the computational photography into the mix, which only really effects still imagery. Then you have the overall cropability and lens line up. I don't care about phone cameras, I just don't enjoy them from an end user perspective.
I just don't think I'm getting stuff like this from an IPhone:
D81_9236 by Marcus Beasley, on Flickr
D81_9319 by Marcus Beasley, on Flickr
D81_8884 by Marcus Beasley, on Flickr
D81_9421 by Marcus Beasley, on Flickr
D81_9601 by Marcus Beasley, on Flickr