I am sure you are right.
Sorry, drifting off topic a bit here, but having used it for just two days, I can't say I am sorry. The D750 is a huge step up from the D7000!
I guess most guys with long lenses point them at the moon sometimes, and I am certainly one of them. This one was taken last night, using the same 500mm f4 and TC1.4EII I have used several times on the D7000. And despite having less pixels on target, being in a built-up area (thus possible light pollution) and hand-holding it instead of putting it on a tripod, there is a lot more detail than I have ever managed to capture with the D7000.