If you need to check out of your hotel before noon but are catching a departure flight later in the day, you can check your luggage onto your Airline at the Hong Kong mainline train station (the one that operates the Airport Express) in the centre of town. That way you can continue to explore Hong Kong, before casually jumping on the train and heading to the airport.Your baggage has in the meantime been transited to your plane, thus saving you the need to check-in luggage on arrival at the airport. A fantastic service!