Today we're using mainly Sony A7RII and I pleased with the image quality (in 99% of the time). But, I'm not 100% pleased with the angle of view I get with our lenses (SK's and Rodie's lenses).
Sometime, we have the lack of wider AOV but we find, most of the time, a way to solve it (if it with stitching or other manipulation).
For most of our work, no doubt that the Sony is robust and very good camera to use (although I hated it at the beginning as a Canon user I had to change my workflow and learn the new buttons order). But, sometime I ask myself "does a medium format will gives me more than I have now?"
I really don't know to answer to that question because I never had a MF back.
I can rent a MF back for a day, but I will need to spend too much money on adapters that I might not need in the future.
We use a lot of T&S and perspective correction (rear T&S + R&F) when we do advertising photography and expensive jewelry.
Does MF can gives me more?
How is the Aptus 8 as a back for T&S?
I don't want, and I don't think it the right time for expensive backs.
*Our main system is Ultima 23D/35