I am very much looking forward to the new A7r2. Currently i am using the A7r on the Actus with a bunch of Digitars, Apo-Rodagons and Schneider HM lenses.
It's a fantastic system, the only thing missing is a way to tether the live view to the computer, currently I am using a Extra screen via HDMI, which is ok, but missing out on many features live view tethering offers.
I haven't read anything about the tethering features of the mark2 , but I am not holding my breath.
Currently I am working on a free project with that combo, where we use the rather dim light of my studio's basement for stills. 8 second exposure with beautiful colors and fantastic detail.
I don't expect to have a much better image quality with the new camera, but the current one is such an unpleasant camera to shoot handheld, starting with terrible ergonomics, continueing with a horrible shutter, both sound and pressure point, to the strange looking EVF and the worst menue currently on the market.