Good news for those from the USA coming to Oz:
Global Entry and Nexus/Sentri Users Now Eligible for SmartGate in Australia
... members of Global Entry or Nexus/Sentri are now automatically eligible to use Australia’s SmartGate automated border processing system when arriving in the country. No enrollment is required and travelers can bypass the passport/immigration lines and proceed to a SmartGate kiosk. ...
Smartgate is automatic entry rather than seeing an immigration officer.
Australian Customs - Smartgate
Smartgate - US Global Entry Program Trial
US Global Entry Trial brochure.