I'll be interested to see what you think of it Raymond, I tried the A7/R III at the camera show and didn't like it from the time I had with them, not so much in performance but in terms of usability/handling.
I know it has a few customisable buttons, but most things seemed to be hidden behind menus. It didn't feel that comfortable either with not much space between grip and lens.
I'd like to try an A7R III or A9 for a weekend but my initial impressions were not very good, hard to explain but there was just something that didn't feel right.