Did you use it during the free trial? I've found it give you just enough control. It's leagues ahead of what I saw from heroku as far as java goes.
They were great when I asked for more resources and the like as well during the trial. I've found a VPS better for my own purposes, but I'm kind of an outlier as far as the kinds of things I develop. Most people don't need that fine grained of control.
Openshift itself is a great model. That doesn't even count HN's love child Docker throwing their lot in with these guys.
I wouldn't mind evaluating their enterprise offering if it becomes relevant. I'm sure the paid product is much better than what was in the free developer preview a long time ago.
At least Red Hat is sticking by it, I haven't seen much in the way of cloud foundry in the while (keep in mind I haven't looked in to it in a while, so feel free to correct me here.)
I've also tried cloudbees and the like. I liked the fact that red hat is good on multiple fronts. It seems like they're nailing it overall.
That being said: heroku is usually the standard. I'm not really too much of a ruby person myself, I'm sure it's amazing for that though.