Australia Post does not even offer tracking for registered mail sent from Australia - tracking available to me only once the package hits US shores. They apparently track it internally in case it needs to be traced but do not make this generally available.
Australia Post used to have detailed tracking some time ago (> 12 mths) but now we only see the f'kn van, or "attempted delivery" when the courier does a running "card drop and go". I had to chase a registered package to Canada recently, and even on the Au Post system (which is what we were able to use) it just said "Left Melbourne Airport 02 April 2015". The next notification I received from Canada was from an IM on Omega Forums
Why on earth would a company set up two systems, especially where it encourages more customers to call you, rather than using self-service/web?
And USPS customs clearance seems to be less hassle than Fedex. But - USPS service is beyond terrible and delivery unreliable. It's one reason why some courts have been forced to adopt alternative means of serving legal documents.