I like the lighter weight and love IBIS for my EF 16-35 f/2.8L II and EF 24-70 f/2.8L II. The low light capability is great. As I gain more experience with the body, I'm finding it easier to operate, but the ergonomics for my big hands continue to be a challenge.
I wish it had a joystick. (I dislike turn and click control wheels.) The balance of my issues with the A7RII are minor niggles, some of which may very well disappear as I grow more comfortable with it. Time will tell.
Overall I think its a keeper, but then so are my Canon bodies.
YES to the joystick. That would instantly make things so much better.