ajz,
No responses yet, so I will let you know my experiences with an a7r, NOT the a7 or a7II.
Canon lenses work fine as long as you are not relying on autofocus. They focus accurately but are mind numbingly slow with a metabones. I don't know if the II is better. I believe there are some threads on this somewhere...
The IS seems fine on my Canon 70-200 f4. Again, no idea how it compares with Sony's IS.
Dave