Totally agree with that.

Recent post to WA on 14th April.  As always over the counter, and have tracking number.  7 days later, check via Aust Post web site - no information other than lodgement at PO.  Leave it 3 more days - same result.  (I had become aware that there had been a train derailment somewhere across the Nullabor on the 10th, and figured, yeah that could affect things).  However on day 11 decided to ring Aust Post.  Investigation instigated, reference number, etc., then another 4 days - positive result.  Parcel delivered. Late due to the backlog caused by the train derailment.  

But I was at least able to keep my buyer informed on what I had put in place.  Item received was happily used that same night.

My opinion is, best seller 'protection' is to lodge over the counter at the local PO, keep your receipt with tracking number, track it, and if there seems to be any sort of hiccup, ring and instigate an investigation, and inform your buyer as to what you have put in place.   You, as the seller are seen to be doing everything you can to ensure the buyers item gets from you to them.

Just noticed this was an old thread, however, I believe Davewil's comments and mine are as relevent then as they are now.