Unless it has changed since I last look Dokku only runs on a single server.
The other major difference is that software like Dokku is trying to run anywhere. Because we are only trying to run on AWS we do not need to build custom schedulers, load balancers, routers, etc. We believe this will reduce your operational costs over time.
As one of the dokku maintainers, I wholeheartedly agree with ddollar. Convox seems extremely interesting to me, since our goal is a single-server heroku experience. I personally would never be able use Dokku in production exactly because of this, but its quite good for throw-away sites, as a test-bed for side projects, etc.
Good work ddollar. I quickly looked at the github repos and once I saw your name attached, I knew it was going to be a quality project :)
