Can you speak in more specific terms about what those changes were with the A7r II?
G
I think people feel you're asking them to explain their needs or preferences in terms that make sense or would apply to you, and that puts them on the defensive. The reasons are necessarily specific to the person and his or her style.
If you just want an answer to your specific question from one person, then the A7rII does something I needed. I take/make/create BW landscapes and had been using a Monochrom camera, because I wanted to emulate something like a 'classic' BW landscape style while focusing on a different aspect of 'nature.' (The catchword for this is 'repurposing.') I needed the resolution offered by the the MM (without Bayer array), but would also have liked to be able to use color-to-BW conversion sliders to control tonal balance and contrast. I didn't want to use an A7r for this because most of my exposures fall into the range where it tended to generate shutter shake. The A7rII solves this problem: no more shutter issues, and apparently because of the new sensor, the image quality of its color files, when converted to BW, closely matches the IQ of MM files made without a Bayer array. It may even do better in separating highlight values. Compared to MM, the A7rII offers the advantage of live view, which was important because with MM and the wide lenses I usually use, I was limited to the rough approximation offered by external viewfinders. I'd been limited by a kind of post-visualization, where I had to take the picture first to see what was actually going to be in the frame.
I don't expect these choice-parameters to apply to you, nor to most other folks; it's a 'fit' between a certain piece of equipment and a style that interested me. I've spelled it all out because I don't think it makes much sense for folks to try to justify specific technical choices to others, except in the broadest terms and through constructive suggestions. Otherwise the interrogation can go on forever: Someone might come back and say 'Why don't you use a digital back or a technical camera?', and I'd have to reply that I have a bad knee and need light equipment. We could go on and on trying to justify our personal needs or preferences to one another, but it really doesn't lead anywhere. It's just the main features that people have mentioned – better AF for some, smaller size for others; file compatibility; presence/absence of EVF or LV, viewfinder lines, etc., that matter to individuals.
IMO we can compare notes about a yet-to-be-seen camera best if we consider features and changes that might affect our work, without having to justify or refute what will turn out to be personal needs/preferences.
Kirk