I once asked the question, "How long is too long at the lounge?" Personally, I like to get there as early as possible and take my time drinking, eating, and mingling. Before my SQ flight to Moscow, I arrived at the Amex Centurion Lounge in Houston hours before my flight, excited for what may be the best airline in the world in terms of service.
It's a Hyatt Place. I've stayed at enough of them at this point to know what I'm getting myself into. The room is spacious, the bed is comfortable, but the soaps, cleverly named 1-2-3, are nothing special.