I've deployed all three - RDO, Ubuntu OpenStack and Mirantis. Several times, for trials, demos, labs, toys and production.
For what Patrick is doing I wouldn't even consider RDO. The level of understanding and detail you need to do anything more than their single-node virtualized demo deployment is not worth it.
Ubuntu all day/all night for a simple "try it out" lab deployment.
That said, of course, we are deploying RDO in a very large way for our company (thousands of CPUs in a few dozen sites). But the choice has a lot more to do with their support organization than it does with their packaging.