Anyone contemplating adapting their Leica M or Zeiss ZM glass to Sony shouldn't hesitate. Rangefinder and other legacy lenses 35mm and longer generally do not have the corner smearing / colorcast issues on the A7R ii, and 21mm and longer have no issues on the A6500. And, of course, if you want to go all in, the Solari UT thin sensor modification ($300 and change) eliminates issues with wide angles. Throw the Techart Pro adapter in and you get autofocus to boot.
Attached photo is typical example (Zeiss ZM 35mm 1.4 on the A6500, at 1.4, autofocus via the Techart adapter).