And I looove the Df and the Zf just as much, but for different reasons. The Df was my daily companion 2014-2022. Now it needs an overhaul (problems with sealing rings and buttons).
Not sure the Zf career will last as long; we'll see.
Biggest loss: OVF
Biggest win: focussing aids, and IBIS.
Note that I use manual focus lenses most of the time, old and new.
Image quality is very good in both cases.