Whether or not the risk is marginal depends on the circumstances of the user. I there's probably a time and an place for this security model, though I don't see myself using it.

I see two key questions:

* Has the security model has been properly implemented?

* Have its properties have been communicated to the users of the system in a clear enough way that people can evaluate how the risks apply to them?

I don't know about the first question, but on the second they could certainly stand some improvement.