I know one or two that have done time, and I also know a couple of prison officers. I haven't any first hand experience of these institutions, but my opinions are based on theirs.
I wouldn't argue about rehabilitation, but it means that the prisoner wants to rehabilitate. There are schemes for them in place, but the success of them are quite low. So, make prison a deterrent. Make it hard work. It may make the repeat offenders actually want to rehabilitate.