To me, right now, it is all about the experience and how the camera works.
IQ is good, but a technical camera is still much better at shooting architecture then the T/S lens designs. Having independent x and y movements and tilt/shift that is not dictated by how you need to shift is a real plus. Not to mention the back shifts, not the lens, keeping my perspective in line. I can never go back to working with those T/S lenses; I just never felt conferrable with using them.
I was at one of the XF events last week and I really liked the camera. (I really hated that my P45+ will not work on it and will not consider buying until it does!) The way it felt in your hand was really nice; you could wrap your entire hand around the camera and really hold on. The view finder was nice and large too.
Before going, I was kind of skeptical with how well it would work with the WLF, being that the handle does not pivot. But they added a button at the base of the camera so you could use it like an old Hassy, very nice.
They also had a Sony A7r boomed above the camera and connected to a TV when giving the demo, so we could all see the controls. Afterwards, I picked up the Sony, and although I knew it takes a great picture, it did not feel nice. The handle was not long enough so my pinky finger could fit. Also, it was too thin; I had to hold it with my finger tips, thumb and the top of my palm. My mid and lower fingers were not flush with the camera, which I could tell would eventually cause my hand to hurt if I used it all day.
Sure the XF is heavier, but it felt more comfortable to hold. My girlfriend felt the same way too.
Of course, in CB's case none of this matters. He is still using the Sony on a tech camera and never shoots handheld. I think his system looks pretty cool. However I just would not want to deal with a bellows camera outside of a studio and it does not look like you can attach the Sony to a plate camera.