I'd also like to hear someone's experience with RethinkDB. The admin interface is fantastic.

slava @ rethink here. There are dozens of production projects built on top of Rethink. We're in the process of working with the customers to publish case studies (rough ETA on this is end of summer).

FYI, here's a list of things to do before we label Rethink production-ready: https://github.com/rethinkdb/rethinkdb/issues/1174 (though Rethink is already really good for doing real work).