I use pow with [the powder gem](https://github.com/rodreegez/powder) and enjoy it; it's very much a set-it-and-forget-it process at this point. Things work out-of-the-box; however, I did get bit at one point because of a *very very very* odd issue where I was using an external gem using EventMachine and it wasn't interacting with Thin correctly (it was shutting down the server because it called `EM.stop`) and Pow didn't expose the issue - we caught it on staging and had to change the Rails server from thin to webrick on heroku. Again, it was a really tricky situation but the only I've seen in the last year+ I've been using it.