Huss
Veteran
For me it's all about being able to use my rangefinder lenses. I can continue to do that without IBIS or a better battery, or a new cam, but I do believe the backlit sensor does better with adapted lenses and I would like a silent shutter option.
It's the thickness of the sensor cover glass that determines how well rf lenses work, especially with regular and wider lenses. And the Sonys have thick cover glass so they are not so great if you peep.
They do work great with legacy SLR lenses.