Personally I don't really care about video (you don't need FF for quality video performance) but would rather be looking for photographic performance for my landscape photography such as:
- low light performance (similar to the 645Z)
- this means max 36MP (24MP better) in FF and 20MP in APS-C mode
- dynamic range (about 14EV)
- a proper set of FA (super) wide angle lenses (prime and zoom) from 14 to 28mm that can hold a grad filter holder
- in body shake reduction
- in body wifi capability to transfer my picture to a tablet whilst on travel
- customisable APS-C lenses mode
- tiltable rear screen for lower position shooting with tripod
- in body GPS capability
- A body that isn't too bulky
- a new set of FA limited prime lenses
- dual SD card reader
So not too much in summary...