I looked at Ranger (which is owned by RM anyway) and found that as much as it could do what you need in the end, it'll take a lot of work to get it there, there's a lot of tweaking to do to getting working to give a seamless transition. I plumped with CC4 because, like you, it gives the end users more or less the same experience that they are used to and gives the ability to farm out non tech issues (like passwords and printer credits) to trusted users.
It's a great idea in principal, it's just badly thought out and done. Even worse is the fact that they don't seem to care....