I predict that an A7SIII will be announced next month with GH5 like specs (probably not 10bit though?) with monstruous AF, dual SD, and lots of improvements. rumors have been going in this way for a long time.  Worth waiting IMO.  GH5 with speed booster and shit AF is a no go for me in 2017. Even though I am buying it for my patagonia trip (the best camera is the one available now.....) I might get rid of it asap.