At a meeting with an ESRI staff member, our organization was told that Portal is not being used in a production environment other than in huge Federal environments. We were told it is very complex (which I don't doubt) and that most organizations can achieve the same results with web configurations and ArcGIS Online. So my question is "Is your organization utilizing Portal in a production environment successfully right now?"
Yes, we have different clients in Kuwait using portal successfully. I should admit it was a bit complex at the beginning. I believe the named-users approach is the future.