You obviously hit post reply moments before i did! We've flown out of terminal 3 twice using this system and it went very smoothly -- coming back was just as slick! Same process, feed your passport along with the customs form you filled out on the plane into the machine and it spit out a paper to hand to the agent at the end of the line. Pick up your luggage and then give that slip to the agent as you leave the luggage area.