We recieved our Leaf H1 to RZ adapter plate today. OUr Aptus 75-S fit fine on the plate, focus was dead on. There are 2 cables that come with the plate. If you wish to capture only from the camera release, you only need the flash sync cable attached. If you also wish to capture from LC11, you also need the camera control cable - both must be attached to capture from LC11. Everything worked perfectly with our 75-S. It rotates the same way a film back would.
I also tried our Sinar eMotion 75 on H1 plate with it, and that worked also, although Sinar has their own RZ adapter anyway. But if you wanted to save about $1,000 and have the convenience of mounting the Sinar 75 with H plate directly to the RZ, instead of unscrewing the H plate, then screwing on the Sinar RZ plate, this works. The Sinar RZ plate for the eMotion 75 is $1,733 and the H1 to RZ adapter plate from Leaf is $783.
I tried to mount the digital component of our H3D, but the H3D digital component has a little locking latch on top that is unique to the H3D, and that prevents the latch of the RZ plate from sliding over. However, I did make a capture by holding the digital component up to the plate (with light leaks, of course) and - set to flash sync - it makes a capture. So, I believe if someone wanted to, they could use an H3D digital component on the RZ with this plate if they had a machinist pare down the RZ latch about 1/8th of an inch or so. Which actually makes the H3D quite more versatile than thought, since this now allows an H3D to be used with view cameras, Mamiya RZ and Fuji 680.