What you need to keep in mind that Polymer is largely experimental software, I would not recommend it yet for generic audience websites. The polyfills are nice, but you have to keep a tight eye on performance, and a new browser release could very easily pull out the rug from under you, as the Chrome release last month did, and make your site not work for a large chunk of users. I personally would not do it if I had a whole bunch of browsers I had to test every single thing in.
It also takes a little while to get accustomed to the Polymer way of doing things. Our app is a single page webapp and there's many things we had to find out for ourselves. Most Polymer documentation is about rendering views, not writing controllers or models that suit web applications.
From what I heard, they are working on a tighter integration with Angular. If that would become an official thing it would probably improve their opinionatedness on controllers/models. I personally am not a fan of Angular, so perhaps I would not follow that anyway ;)