When I was in Aus back in December, I popped into my old aero club to ask about conversions as I read what was on CASA's website which was an beauracratic nightmare. The CFI gave me a quizzical look and said that, apart from having an ASIC or AVID issued, it is about the same as a FAA piggy back licence (but I don't think you have to pick it up in person and I think some of the bureuacracy is actually easier). He pointed me to the application form itself rather than what the website had to say, saying their website was often out of date. Check out
https://www.casa.gov.au/sites/defaul...form-61-4a.pdf
These days, getting an ASIC or AVID can be done in about 2 weeks if you are in Australia - just pop down to an aero club where the CFI or someone else is designated to receive the docs and there are now private companies that do the whole process. Shows how utterly useless it is, but they can't backtrack on it as it would be admitting a monumental stuff-up. It is crazy to think a terrorist would storm Birdsville airfield, but it is designated such an airfield because it probably had a schedueld flight or a mining company flight at one stage in its life.
I am about to embark on both the FAA and Aussie system - I have just taken part ownership in an N reg a/c here and I am intending to be in Aus next year for either 6 weeks with the family, or if they baulk at that, for about 4 weeks including going to the illustrious Birdsville Races.. I will let you know how the application process compares for both.