I understand that having a CIR is exactly that - the PIFR needs to be issued seperately in order to exercise its privileges.
IF you have a CIR, you can be issued with a PIFR automatically but it must be entered into your logbook. Very, very useful for maintaining currency. ILS out of date ? its OK, do one on an PVT leg and then hey presto - its 35 days for your CIR.
I used to believe that the PIFR was dangerous but I've come to the conclusion that its all a matter of curency. By itself its great and the skills you pick up getting it are invaluable but like any complex skill, you need to practice.
When you need it most (in IMC to minima) and you are not confident and current, you are at great risk of coming unstuck and hurting yourself and others.
My only advice, IMHO, is an enroute PIFR is a recipe for disaster . You need to be able to get down at the other end. The cloud will always be lower than you hoped
