Which is great.. until I do a google search for my closest movie theater on my phone to pull up the listings... the link to that theater's page is right at the top... "great" ... now I click the link and the site redirects me to m.theater.com/ (no path after the slash) ... now I'm stuck slogging through several pages to get to what I wanted.

This happens a lot.. there's a page on the desktop site that doesn't correspond. Responsive design still shoves a lot of extra resources at a client that the smaller devices especially don't need. Responsive rendering then loading an adaptive client in the browser is a better option... browser sniffing is the only way to do this.