I handled one the other day. A pre production prototype obviously.
Lighter than you think, but not as light as Hassy offering. If you're used to an X1Pro you'll get this.
Was impressed by the selectable full sensor AF points, a first for MF. And the EVFs movable tilt/rotate option seems excellent. The standard lens is a bit longer than ideal -would have preferred a 50/55 on crop sensor. Battery was huge and unique to this camera. That's good (life) and bad - no alternatives, takes up a lot of space. I really think a Canon or Phase One style battery would have been fine.
Couldn't test the image quality/files obviously. No convertor even if they'd let me put an SD card in. Was reasonably quiet, but not much as new Hassy, though a 'quiet mode' might yet be in the final firmware.
It's very promising all in all. I pray for Capture One support, and for a quick upgrade of that sensor to next gen 75/80 mp soon. Late 2017 in my dreams. I've got so used to 100mp, that it's really tough to step down so much.