Before the Coffee has posted a tireless shutter shock comparison that faces off the Nikon D3, the Sony NEX7, and the Sony a7r. The conclusion is as follows:

“Duration of vibration is greatest for the A7R over the D3 and NEX-7. This confirms what we already know; the shutter has to close, open, close and then open.
Intensity of vibration in the A7R is about the same as a DSLR but the A7R dissipates the vibration faster than the D3. I am pleased to see that the A7R is not off-the-charts in shutter vibration. It will probably impact image quality at high zooms but most of my shooting will be 100mm or less. For those that like above 100mm, it would be great if a firmware update for the A7R would allow us to raise the shutter into position prior to exposure, much like mirror lock-up.”

I have found no problem with shutter shock for strobe photography. Shutter lag and shock are high on the a7r and can be expected to exert influence over the final image in slow exposure photographs.

Again, here are my thoughts about the a7r.