So I'm sold - I'll be buying three Octopus cards for my family of 3 when we visit in November. We'll be arriving by train from Guangzhou and departing by plane. I've read the thread but I'm still confused by the airport express references. Can I use the Octopus for the airport express when we are departing? Or is the airport express cost just deducted from the Octopus card?
Where in the train station do I buy the Octopus? And can we return them at the airport as we leave Hong Kong?