Thanks everyone. 4.5 hrs on the way to syd, will just stay in terminal. 9.5 hrs on way back, will exit and re enter. Will be carrying absolute minimal stuff in a small backpack, will just carry it around city.
Whats the process for arrival in HKG, exit to HK and then reenter to take a connecting flight? If i'm on time, i'll probably leave for 6 hrs or so I guess. Are there any hang ups I should be aware of?