I should be careful here, 'cause the last time I praised AustPost, my entry went missing (turned up back at my place a forthnight after the event, for some inexplicable reason) BUT...
...despite being everyone's favourite whipping boy, I've found that AusPost is cheap, simple and reliable. And remarkably fast.
"It got lost in the post" is just an excuse for the seller being useless/lazy/greedy, 99.9% of the time. If AusPost was really responsible for losing even a tenth of the things they're blamed for losing, then they'd have had about thirty Royal Commissions by now...
I use either of two post offices (the one near home, and the one near work), and the staff are generally pleasant and friendly at both - the only hint of an exception to that is the sour faced old lady at the Belco PO, but you'd never call her rude or unprofessional.