We have a real world network called Hyperboria (http://hyperboria.net) with various services (irc, video, social). Latency depends on the amount of peers you have and how well connected they are.
To be fair, one would think it would be a bit more complex than that. Think about how large their codebase is and how many different types of browsers and devices they support.
While this isn't what commotion is using, its what we are using for Project Meshnet. "Cjdns implements an encrypted IPv6 network using public-key cryptography for address allocation and a distributed hash table for routing." https://github.com/cjdelisle/cjdns