Well, just quietly (speaking as someone who has also done the US instrument rating) when you can read through a question bank and just continuously review the Q's and the A's...not sure I think that makes you really think. Now, I'm not saying that makes you or anyone else with a US instrument rating a bad driver. However, if you can wade through the documents in Australia and are comfortable enough with those docs (and the regulations and information therein) then you should be able to pass the IREX. A big point on the IREX is that its a CASA exam and therefore as much a test of english comprehension as it is of the regs themselves (which is a bad thing, admittedly). First and most important point, read the f-ing question and ALL the answers before you tick an answer. If you are interested, I have some additional advice which might be helpful...PM me before the end of Thursday and I'll give you the good goss.
HP