24-85mm f/3.5~4.5, the NEW, VR-equipped model (Nikon has made several different versions of a 24-85 over the past four decades) that was DESIGNED specifically for 24-MP FX cameras...it's a NEW design, for a new era. It's low-cost too, since many tens of thousands of them were sold with Nikon D600 bodies not too long ago. Smaller, lighter, handier than a 24-70. The difference between 70mm and 85mm is very noticeable,and significant.
Do you realize that a 24-70mm f/2.8 is a large, bulky, pain-in-the-ass-to-carry-around lens? You might want to check one out before you commit to a lens in the 40-ounce size class, especially if it will be paired with a small-body camera like the D750, depending on what types of uses you're planning on using the lens for. For "working" use in social situations, 24-70 is good for CLOSE-range stuff and where you truly need lens speed; the 24-85 is more of a travel/utility/portraiture lens where you're more likely to be shooting at f/5.6, and want a smaller,lighter, easier-to-pack lens, that's also longer, AND which has Vibration Reduction for shooting in lower light without a tripod, or for slow-speed panning shots, etc..