One thing, depending on the time, don't rely on getting a Lantau (blue) taxi quickly when you call. You've lived here before and know the taxis are "regional". There are a very limited number of Lantau taxi licences and, again depending on the time, you might have to wait at HKG for one and have a longer wait to get one back to HKG. I lived in Tung Chung for a few years and could never rely on the taxis; everyone would take the buses.