In MEL's defence they now have a separate crew priority line in the International hall at peak times; see, the visit to Officeworks for materials for a sign wasn't that hard! And most of the Customs and Quarantine staff are now actually quite polite. I think that there is construction in progress with areas walled off which is making the baggage hall more of a zoo than usual.
However, the airport still has along way to go to be world class. And Sydney is just a national disgrace.