Agree with FCO!
My experience is the other way - CASA to FAA.
Do NOT treat IREX lightly. In my opinion it is the toughest of the CASA exam suite. An IR flight test is the same everywhere - numbers/standards must be met! Personally, I found the FAA oral examination to be akin to the Spanish Inquisition and the flight test to be much simpified due to the professionalism and helpfulness of the FAA ATC.
