There was a great article in Australian Flying magazine just recently on this very subject. If I can find it, you can always ring 'em up with the month and order a back issue.
I think the main advantage the PIFR has over the CIR is that you don't need to keep current and I don't think renewals are an issue?
CIR is fairly straight forward to keep current, provided you have the required navaids within reasonable flying distance. To bad there aren't as many ILS/LLZs as there are NDBs in the top end though!
