I am personally using it for networking in a WebVR side project (which is far from finished), where the challenges are the differences between clocks, interpolating between received positions, and more. You can try the current version here http://guido.io/WebMetaverse/ (open it multiple browsers and observe).
I ended up implementing a signalling server (in Elixir) and client, which made me understand much more of what is going on under the hood.
https://github.com/nplab/WebRTC-Data-Channel-Playground
Speedtest for example
https://play.google.com/store/apps/details?id=com.airboss.ai...
It's far from perfect and has some obvious shortcomings but it works reasonably well with low latency.