Luckily I have had nothing but good experiences with Australia Post. Even the subcontractors who deliver parcels in the last three places I've lived have been friendly and responsible and I've never had anything go missing except for that one time I bought from a dodgy new zealand clothing site who conveniently had an estimated shipping time of 30 days or more to eliminate paypal disputes, got my address details incorrect and refused to refund me even though tracking information showed the goods were returned to china

Their costs however... sheesh. I've noticed an increasing number of letters delivered but with their postages tamps unstamped which I think is a silent protest on the part of their postal workers who are seeing prices skyrocket but no improvement in the service provided nor their working conditions.