Still in "beta" - as most google products. They think the process is so linear, when it is not. The jury is out on whether it will increase VDPs -- would you rather want your customer on a GMB VIN info page that you have little/no control over? Or your website VDP? Seems like it just adds another click for the customer. Lastly, it doesn't allow for promotion/specials.
Google wasn't happy with dealer mobile websites, and this was the solution. Remember, this only shows up on MOBILE (for now)
And lastly -- remember that your GMB primarily (I have heard over 90%) shows up only when someone searches your DEALER NAME. Dealer name searches are better off on our website.
I would say we just keep a close eye on it, and the reporting that will be coming out of it. The initial stats from a few dealers - decrease VDP traffic from mobile devices.