Hi Chris,
I share your concerns. Generic search rankings seem pretty useless these days. Google is going to take a variety of variables into account for any individual user (especially logged-in ones), unless they're literally searching in incognito mode. Throw in all the map data and that's more non-website info mucking things up. Google Webmaster Tools has rolled out some more robust keyword data recently, and I think that is probably the best bet. You can see all the keywords your website made impressions for and related data. You could also create some geo-based Google Analytics reports to monitor organic traffic from users in your desired geos.
That will at least tell you the current reality of your website with more accuracy. However, It won't tell where you rank for some arbitrary keyword phrase for which you wish to gain traffic, if you aren't already receiving impressions for it. I guess that is where the Moz Ranker would be most helpful.
