The main advantage for the PIFR is that it is good for 2 years. I was flying an aircraft that was the only one of its type in Oz, so searching for a testing officer once every 2 years was far better than doing it annually. It really galled me to have to pay for a CASA FOI to fly up from Melbourne, pay his hotel costs, pay for the review, and then let him have a fly at the end of the review because he hadn't flown a helo of this species, let alone the sub-type, since a basic endorsement 10 years previously. In no way was he current on species, and had zero knowledge of the systems in the type.
In addition, the renewal is a "Review" not a "Test", so if something isn't up to speed, instead of "You failed, take me home" it is "Let's try that one again".
I still did the whole shebang of approaches and enroute approvals, more paperwork than the CIR, but overall far less stress.