When the barcode scanning system is used properly it works really well ...
Posted a parcel to WA on 13/11, buyer emailed on 19/11 to check on estimated delivery date. I was able to check tracking and tell them that the parcel had been delivered to their address, and signed for, that morning.
Posted a parcel to another Melbourne suburb on 16/11. According to the Aus Post site the current status is
17/11/10 06:30 Onboard with driver
Maybe the driver is taking it for a long sightseeing drive around and around Melbourne!