yes the AF is better on the Rii
I don't use tracking really, but 117 phase points should do well for me on the a7II
the Rii has 399
I mean I only use 11 on my D700
don't know if all else is equal
Matt, you use an A7II, right?
how is the higher ISO performance and DR ?
Frank, I have the A7, not the A7II. However, the sensor to my knowledge is the same with maybe a few tweaks that don't affect IQ much. I find the output (ISO performance, DR) to be just as good as my D600 which also bears the same sensor. I have to say that I greatly prefer the both the native jpeg output and ACR RAW conversion of Nikon files to Sony, and the auto white balance of the Sony is more problematic for me. When comparing the A7 to the A7II, the biggest difference is that the green ghosting from point light sources is almost gone on the A7II, and I HATE it on my A7. As you have a D700, which I also had prior to my D600, I can say that you'll get much more apparent detail from the A7II than the D700, and better low light performance, and better base ISO DR for shadow recovery. The key on these sensors is to never blow highlights. But it's crazy what you can get out of a RAW file from shadows. What seemingly appears black has a ton of info when you push the shadows.
Sony auto-ISO is painful on my A7. In A-mode it defaults to a minimum shutter speed of 1/60. My workaround is to shoot in M-mode in low light while leaving auto-ISO engaged so I can drop the shutter speed down for static subjects, and A-mode in bright light. Fortunately the exposure compensation works in conjunction with auto-ISO in M-mode, which it did not do on the NEX cameras.
One other thing to keep in mind. Engage the first-curtain electronic shutter at all times unless you find your shutter speed faster than 1/1000, where it causes a dark side of the frame. I'd bet that with it engaged, you can shoot handheld with a 25mm Batis at 1/25 second and get sharp shots all day long even without IBIS, and half that with it engaged. I used the image-stabilized 16-35 on my A7 in Italy recently and in dark cathedrals I could shoot at f/5.6, 1/10 second, ISO 800-1600 and get crisp shots all day long. For those situations I usually use the 2-second delay timer so that there is no motion from depressing the shutter release. I push, gently cradle the camera and lens, and the exposure is motion free with the electronic shutter.