I am using WebRTC with a MMO server cluster written in Golang. Basically, I got Simple-Peer WebRTC library to run on top of node-electron in NodeJS. My Golang coordinating server then also coordinates a farm of 4 NodeJS processes which basically run as UDP proxies. The complexity of WebRTC is tamed by Simple-Peer.

One downside: Getting node-electron to run takes some wading through shared library installs to satisfy Chrome dependencies. However, this turns out to be a series of straightforward responses to error messages. Another downside: I'm wasting some memory and swap on Chrome dependencies I'm not using. In the case of my game, I'm always going to be more CPU/bandwidth bound than memory bound, so this turns out to be a non-issue. A third downside: WebRTC uses up 72 bytes of each packet with its own header information.

All that said, it appears to be running like a champ. It also makes a big difference in the play-ability of my game in poor network conditions.