I have limited experience with Heroku, tested the beta for a bit. For small/development apps I say you can't go wrong. I don't know anybody running production apps on Heroku yet, but it wouldn't surprise me if they are.<p>The Heroku guys are friendly and competent. If you don't have a dev environment, they provide one for you. If you have your own, their gem makes it cake to sync your changes to their servers.<p>My only beef would be that they have a custom Rails install that you're forced to use, so you lose a little flexibility, but all in all that's not a major hold-up.