I have mostly Nikon lenses and gear, but also have an A7S (first generation).
I made the decision to use manual focus and manual exposure on the Sony, using some of my Nikon lenses and inexpensive adapters to use them with the Sony (so that I can keep an adapter on each lens instead of getting a single adapter and swapping lenses at the adapter level).
It's obviously not as convenient as using lenses made for the camera (or using a more expensive adapter that can retain the auto features of some of the Nikon lenses).
For the things that I am using the Sony for (or that I expect to be using it for), it's not much of an inconvenience
(I use it for fledgling experiments with astrophotography, and for time-lapse movie-making, and for still-life product/documentation photos, but not for general snapshots, etc.)
For the occasional new lens purchase I still buy Nikon glass, because I think of the Nikon as my 'primary' setup.
YMMV...