Hi
Here is a short brake down of the latest generations cameras.
Mamiya AFDIII / Phase One AFBoth are the same camera with different branding
Can shoot film
Can be used with P and P+ series camera backs.
Mamiya DF/ Phase One DF Can be used with Leaf Shutter lenses
Can be used with V- Grip
Can be used with IQ1, IQ2, IQ3, P and P+ series camera backs.
Mamiya DF+/ Phase One DF+ Can be used with Leaf Shutter lenses
Can be used with V- Grip
Has automated liveview
Faster Auto focus
Can be used with IQ1, IQ2, IQ3, P and P+ series camera backs.
Phase One XFCan be used with Leaf Shutter lenses
Can be used with V- Grip
Has automated liveview
Even faster Auto Focus
Has removable prism with Waist Finder option
Hyperfocus option
Focus stacking option
Integrated Profoto Air flash trigger incl Flash analysis tool.
Vibration analysis
Can be used with IQ1, IQ2, IQ3 and IQ4 series camera backs.
There is much more on the XF but this is a good list of main differences.