They announced during their 1.0 release that Flynn is now production ready but I have to disagree at this time. I do honestly love the idea of running my own Heroku but it's just not stable enough and doesn't recover well if a node goes offline without manual intervention using the flynn-host fix command (and sometimes that command just chokes up completely).
Next time it happens (when, not if, at this rate) I'll try to set aside some time to gather up the logs to help debug the problem but I'm using Flynn to avoid the sysadmin side of things and just build my product. In my opinion Flynn is tinker-ready, not production-ready. It's infuriating that it has these random problems because like I say I really _really_ love the product and desperately want to be able to use it reliably.