Outbound SYD T1 with an Express Card gets a much shorter Immigration line (kiosks) and faster security. Its usially beneficial.

Arriving at SYD T1 with an Express Card at Customs (after Immigration) means about zero. Everyone is in the same queue and the CBP Officer decides how you are handled - when questioning the guy about Express Cards, he said they are useless and only serve to make you feel special when given out on board. As for Immigration, just use the kiosks (if your Passport is accepted) and then head to the auto machines. Ignore the Express line - it only causes confusion.