FWIW, I've used Heroku as a production environment at multiple jobs. It works great there as well. The primary issue in my experience is cost. If you need to serve a lot of traffic, Heroku gets very expensive very fast. But it's still easy to use.
That cost can be offset by the fact that you may not need to hire a dedicated devops engineer right away, and your other developers spend much less time dealing with server setup and debugging.
