As they are still in short supply in the UK and because I am off on holiday soon I'll leave purchasing the A7RII until September or October.
I'm in two minds about selling my A7S. The A7R will definitely go. Been a great camera but I am convinced about the ergonomics and IBIS alone to want to go up to the A7RII. But the A7S? Knowing that I have a camera that will really do high-iso, e.g. 10,000-20,000 is very powerful. I am perhaps reacting to having been tortured for several years with digital cameras that couldn't even get above iso800 (specifically my Leica M8) so I'm concerned about losing good high-iso capability.
Of course, if any of you can convince me the A7RII really will do good very high-iso then I'll consider selling the A7S as well. I don't like having cameras sitting on a shelf doing nothing.
Just my two cents.