Just for your information the Royal Hotel is no longer the only hotel near the airport in Hong Kong. The Novotel Citygate opened up last month and I stayed there for a brief stopover last week. They are running a promotion for US$92/night. The hotel is super nice and reminded me of a boutique New York City hotel. They have a free shuttle from the airport if you arrive before 11:30 PM--I had to take a taxi at HK$50.

I didn't know before the stopover but there are semi-private sleeping rooms available in the airport. I haven't stayed but that may be a better option for a short layover.