We're running a Rails app on Heroku but we're not happy with its performance/price, although we like the convenience. Is there any of service that rivals Heroku in terms of the convenience of running and maintaining a Rails app?
I recommend Dokku (https://github.com/progrium/dokku) if you want something similar to Heroku. The nice thing about Dokku is that it's simple without locking you in to any particular (proprietary) cloud provider stack.
We converted from Heroku to AWS+Chef (we use hosted chef from opscode). We even wrote and open-sourced a application_procfile cookbook that lets you do heroku-like things with Procfile web and worker processes.
Moved to Engine Yard after a long search for Safe Harbor compliance... surprisingly quite ok! Using the smallest instances, and its still more than enough for now
Not quite as convenient as heroic but still quite nice in the deployment and configuration sense is engineyard.