The prevailing sentiment expressed in this thread seems to be that RRV is specific enough, while the much larger Sonoma Coast AVA needs a split.
Russian River Valley AVA is 155,000 acres = 62,700 hectares.
Burgundy is 68,000 acres = 27,700 hectares, and this includes Cote de Nuits, Cote de Beaune, Chablis, Cote Chalonaise, and Macon… substantially less than half the size of RRV but divided into 100 official appellations.
The general feeling that “RRV” is specific enough indicates, IMO, just how early California is on the learning curve in terms of discovering (and celebrating) the distinctiveness of the various districts of this huge and diverse region.
As for how easily the consumers get confused, I think we have a chicken versus egg situation. There are hundreds of wineries, far too many for most any consumer to get a real handle on. And in CA, the growers and makers seem reluctant to help the consumer out with designations indicating local geology and climate conditions that influence the wine. And so it is all left to marketing, and wine critic points on a scale of 100 points, most colorful shelf talker wins.
In France, most casual, non-geek wine consumers can make a rational choice (I did not say a perfect choice) between Chablis, Chassagne, and Macon Villages without knowing the individual producers, without knowing the Parker points, based upon the general character of the appellation and the vintage. It will happen here some day, and I say, lets get after it.