>>4405430I have the ZF and I believe the Z63 is just strictly better. But the differences are small enough that if you don't shoot video you can go with either one.
The Z63 has a better viewfinder and an actual grip so if you're shooting for long periods of time it might feel more comfortable. The ZF is slightly lighter but given that most people have a custom grip it's not really lighter in any way. If you like the retro look and don't use long telescopic lens then the ZF is a perfectly fine choice.
I've heard some anedotal claims the ZF take better stills than the 63 because the 63 has a partially stacked sensor but I'm not sure if that is true.