Michael Reichman, in his article about the Pentax 645z, makes the point that how a camera feels and operates will often trump technical specs in his decision making. That works for me as well.
That's certainly true. The way a camera feels in the hand, the viewfinder, live view, the quality of the auto-iso implementation, the damping of the mirror,... are essential for some types of photography.
On the other hand, aspects such as how plasticy a non touch screen feels (and the D750 screen feels very robust to me), .00x % differences in the contrast of the top LCD display, the degree of resistance of the rotative dials in a newly manufacturered camera (we all know those change after a few days usage),... are secundary for anyone intending to use his camera to take photographs.
As far as all cameras offering identical image quality, until the current generation of Sony sensors I was never able to capture comfortably daily scenes such as this one,... always ending up with noisy shadows, un-natural transitions in highlights,... So I don't share the marxist view that everything is the same.
I didn't have to look very far, this image was shot last night.
IMHO.
Cheers,
Bernard