Couple more things you might want to look at:
** While testing I saw a few errors pop up when looking for the _escaped_fragment-= version of pages. Looks like this:
unknown domain: goodeggs-garbanzo-seoserver.herokuapp.com
** Your pages have a lot of boilerplate in them that can confuse things. Consider adding html5 header/footer/nav elements. or just getting rid of much of that from your server-side-rendered output. and....
** Seriously consider adding rel="canonical" -- it's the best way for Google to know the URL you want people to use and it helps to disambiguate your pages.
Regarding mixpanel you can see the unminified JS if you view source here:
Not a huge amount of bytes to be saved, but it can't hurt :)
thanks again. we think the unknown domain issue may have been our custom phantomjs layer being spun down by heroku. we upped the instances so they'll always be ready to answer. also added some rel="canonical" in a few major places.
Bob Zoller, Dec 19 2013 on 1500wordmtu.com