On the positive side, I find XQD such a huge improvement in transfer times to computer (even though my SDD limits the speed to 250MB/s, not the card). I guess that's a lot of catching up to do for wireless transfers using any technology.
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I think the SD UHS-II + XQD mixed slot combination is likely to be found in the D810's successor. Mixed slots has the advantage that any SD card can be used and many of us have those in cameras and other devices. However, I by far prefer the XQD card's rugged housing, and I'd rather not have to invest in expensive SD UHS-II cards when I'm already committed to XQD.
It would be great if the dual area split screen LV zoomed in view that is currently only selectable if the two windows are in the same axis, would be more freely selectable so that I could use it to focus tilt shots in any axis. Currently it is very useful for adjusting focus and tilt when tilting vertical landscape shots, but not useful for horizonals. Any improvement in the live view image quality would be beneficial of course. Currently it is very useful but could be better especially in low light. I would imagine improvements would transfer to video image quality as well.
Some people like a lot of custom buttons on the camera. I find the DOF preview, Fn1, Fn2, on the front side a little too much; the buttons are not in the same relative position when doing vertical shots so I have to search for the right button to find the functionality, unless I basically map Fn1 and Fn2 to do the same function, which I have in fact done. In my D5 setup, both reset the focus point to the preselected focus point of that orientation. I guess for consistency it is best if the D810's successor has the same custom buttons as the D5 so that interoperability is made easier. But I think there can be such a thing as too many custom buttons ... but this is better than none.
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