I just want to say in advance, I agree with everything @mspeer has said so far. This is a very static scene, but if that's what you deal with then by all means ask about it.
Also, for some reason I was not able to get a frame-rate out of Legacy viewports, so I don't have that. Only general feel. For both cards, Legacy Default (didn't test High Quality) was nearly unusable. Camera would have considerable jumps when viewing the whole scene, maybe 7-20fps? The 1070 fared slightly better, but only by a small margin. Frame rate would improve the closer you got to the model or individual pieces. The only different result here was the 1070 in the Smoothed scene, that one had a visible improvement to frame-rate, but was still choppy. That being said, general modeling and manipulations was good enough. With the camera positioned to see the whole scene, moving objects wouldn't be buttery smooth, but enough to not rip your hair out. Getting up close to the model made that a non-issue. General modeling was pretty decent as well, but beveling had a bit of lag to it. Extruding was fine.
Modeling/Moving objects in VP2 was buttery smooth for both cards. Didn't have to get close up or anything, just worked.
i7-6850K (3.6-3.8GHz)
GTX 970 SC 3.5GB
GTX 1070 FE 8GB
BenQ BL2710PT 2.5K Screen (2650x1440) 60Hz over Dual-link DVI-D.
CentOS 7 (1611)
Driver 375.26
Maya 2016 Ext 2 SP2
OpenGL - Core (Compatibility)
* Maya was full screen with the Time Slider, Range Slider, Command line, Help line, Shelf, Menubar, and Channel Box open. So viewport was very large.
Results (All ranges are between having the whole scene centered in the viewport to getting up close to small groups or individual pieces of the scene):
GTX 970
Temporal:
VP2: 110fps - 145fps (Mostly around 128fps - 135fps)
VP2+AO: 45fps Full scene, 70fps close up
Smoothed:
VP2: 110fps - 145fps (Mostly around 120fps - 130fps)
VP2+AO: 45fps Full scene, 70fps close up
GTX 1070 FE
Temporal:
VP2: 125fps - 145fps (solid 130fps - 135fps)
VP2+AO: 80fps Full scene, 95fps - 105fps Medium, 120fps close up
Smoothed:
VP2: Solid 130fps
VP2+AO: 83fps Full scene, 94fps Medium, 120fps close up
Side question, @Anonymous: What monitor do you have, and what is it's rated refresh rate?