A few years ago I briefly had the A7Rii and whilst the image quality was mind blowing it just didn't have some features I like to use so went back to APSC, now, after reading a lot of user reviews I recently took the plunge again with the Riii, why? the main reasons for me were :-
Ability to crop images heavily with little loss in quality, a sort of zoom in feature really!
Bigger long life battery, little need to get a spare
APSC crop mode for an instant 'zoom', assignable to a custom button
Silent shooting, assignable to a custom button
Eye auto focus, assignable to a custom button
and there are plenty more features in the extensive menus.
The main bug bears are there is no time lapse (or indeed focus stacking) feature in the menus unlike other brands, and to make the most of the sensor you need the best glass which can be expensive!
All in all if you want the best 'bang for buck' landscape/travel camera this is highly recommended.
Upgraded this from entry level A7ii.
Super faster, better quality photos even using the same lenses. All the menu is the same so very easy to change over and ready to go.
Very happy with my purchase. It’s like brand, the new quality is perfect, so saved lots of money.