The "Who Uses Redux?" issue in the repo ( https://github.com/rackt/redux/issues/310 ) does list a number of companies, so it does seem like there's actual usage. I also ran across https://github.com/mezod/listlogs/tree/joan , which is at least more of a real app. Finally, the Firefox DevTools now appear to use Redux some as well ( https://hg.mozilla.org/mozilla-central/rev/17d1d8bbae99 ).
I can't say anything for how good these projects are, but they ARE actual uses of Redux that are more than a TodoMVC. Here's some links:
https://github.com/jfurrow/flood
https://github.com/FH-Potsdam/shifted-maps
https://github.com/quirinpa/2post
https://github.com/karlguillotte/Ctfs
https://github.com/madou/gw2armory.com
In fact, that GW2Armory app is the biggest one I've seen so far, including some VERY complex reducers and selectors.
Isn't it ironic that GW2Armory is actually an AngularJS app using Redux?