The Google Elections team is happy with their experience. They write:
"We love writing Dart because it's fast, compact, and sane. Great tools and a readable language give us the confidence we need to move quickly. But adding Polymer to the mix is pure gold. After years of writing code for the web, this was the first time I've felt like I'm working with a real platform. We threw away tons of the boilerplate we've built up over time and just focused on the app itself. This was awesome."
Sean Diamond, new to our team this year, said, "Being new to web development, but having done years of UI development on native platforms, writing Polymer with Dart made me feel right at home. This is exactly how UI development should be done."
The Explorer is built with Dart, Polymer, Core Elements and Paper Elements.