Where companies are in the market (per Thom Hogan)

[Ilkka Nissilä]

The D800 isn't all that good at high ISO. DoF, low shutter speeds, high ISO fuzzed out detail drive me up the wall.

I need a D700 replacement and I hope Nikon does too.

Well, the D750 has excellent high ISO image quality, and is less expensive than the D810. What I don't like about the D750 is the sound of the mirror/shutter, the shape of the grip, and the meager 12 focus fine tune registers available. The autofocus is excellent in low light, the viewfinder good, and image quality is good across a wide range of ISO settings. Unlike the D5, the D750's dynamic range is excellent also at ISO 100.

I think it would be great to have the D750 sensor in a D810 body (or its successor). Maybe they will make one. But I suppose there is a limit to the number of variations Nikon can make. Some like the smaller body.

[Akira]

The evaluation of the ergonomics would depend on the individual users.  My hands love the ergonomics of D750: deep grip and narrow width.  The narrow width makes the camera feel very small.

On the other hand, I don't like the mirror/shutter sound either.  Their shock is also a bit too strong and affect the lowest hand-holdable shutter speed.  Even the mirror is locked up, the shutter unit causes some blur when I do high magnification (x3-5 range) closeups.

The pliability of NEF makes it very hard to leave Nikon.

[Ilkka Nissilä]

The evaluation of the ergonomics would depend on the individual users.  My hands love the ergonomics of D750: deep grip and narrow width.  The narrow width makes the camera feel very small.

Yes, I understand this is very individual. My fingers simply don't bend on such a small radius and it feels uncomfortable to hold the D750's grip. The D810 grip is good for me, as is the D5's.

[David H. Hartman]

I think I'm pushing 40 F mount Nikkor lenses so switching to another brand would be very painful. The only lenses I can't use directly on my D800 are a pair of 55/3.5 compensating aperture Micro-Nikkors. I can mount them on their M tubes or an E2 tube to the D800. That's about 1965 to date for the lenses I own. That's amazing compatibility over the years. 

Dave Hartman

[Akira]

Yes, I understand this is very individual. My fingers simply don't bend on such a small radius and it feels uncomfortable to hold the D750's grip. The D810 grip is good for me, as is the D5's.

Yes, the grip of D750 could feel too narrow for some people.  I like the fact that my finger tips doesn't hit against the body, and it is comfortable and safe to "hang" the camera with my fingers as a "hook" when I'm walk around to look for something interesting to shoot thanks to its depth.