@Swanseajack wondering if u saw this pal
Morning Andrew.
My observations so far.
My first impression was how quiet shutter was, I like to use the camera for birding in the garden and the D750 was very loud IMO even in QC mode. And one shot, off they would fly.
I like the crop modes as you can black out the outer space, so makes it easier for framing. Not sure if this option is available on the D750,?...... The 1.2 crop mode is handy for me now, as my longest lens is 200mm @ f2.8, I was using a 300mmm and a TC on the D750.
I thought the noise was a tad worse, but what I have noticed is that the D810 over exposes a little, and now, I feel it can run at lower ISO than the D750. As an example I can use auto 800 now and on the D750 I was using 1600 as my upper limit. This is difficult to quantify as I'm using a different lenses now.
JPEGS seem better to what I remembered when I first used the D750, when comparing to the Fuji XT1, when I switched to the D750 two years ago, or so.
I find the grip very comfortable and nice like the D750.
IMO the photos from the D810 are sharper and seem to have a little more pop.
Not noticing any problem with file size as I upgraded to a i7 machine over Christmas just gone.
Obviously cropping is better due to the more MP.
Not sure what you want to know Andrew, anything specific?.........You thinking of changing over.
Am I pleased I made the change, yes is my answer at present, but the D750 is an excellent camera and the D810 was a GAS thing for me. I wanted one when I came back to Nikon from Fuji but it was out of my price range then. Both cameras are more than enough, for my skills.