If you find that it's laggy on Firefox, make sure you are on at least 44.0.1 (latest stable at the time of the post). Strangely I don't see anything that would feasibly affect this in the 44.0.1 changelog, so maybe the browser restart fixed it.
Holy fuck, this is cool.<p>We've actually been thinking about this exact problem recently and were considering building something like this. This should prove a great proof of concept / starting point for our work.<p>Awesome.