I was asking a similar quesion here some time ago.

The Arrivals lounge is not available for transit passengers and I think going to the Pier/Wing is too much hassle if going downtown afterwards.

I´d just pay for either the Premiun Plaza arrival offerings or then head for a sauna, shower and swim at the Regal airport hotel. Ok, it costs some HKG dollars, but you are refreshed and out of the airport in no time.