Arca was showing a prototype Canon Mount lens board at PhotoPlus. Aperture control is built in and is actuated by two buttons (up and down on the f/stop scale basically) You can also hold the two buttons down simultaneously to open the lens fully then close it back down. An LCD on the front shows the focal length and aperture. A mini USB port on the panel allows you to power the unit with any USB battery device. I'm going to find the smallest one I can, to mount unobtrusively on the camera. Pricing is supposed to be around 1100 (I believe) with December availability.
I spent at least an hour going over the setup and it works much better than the custom dumb mount I had made for my Canon glass in that there is more room between the standards, so that the A7r2's new deeper grip doesn't get in the way. There was also a version that would mount on an R camera and allow the use of the SLR glass with digi backs (with their FPS)
Arca has also developed a brand new Sony specific L Bracket to insure that the MK2 mounts up nice and square (since Sony redesigned the bottom plate of the camera).
I looked at the Actus for the first time. I still prefer Arcas.
That was pretty much the only thing at the show that I was really interested in. New York is dirtier, noisier and more overpopulated than ever... or maybe I'm just older.