Depends on who lands ahead of you. If you come in just after the Chinese a380 and the New Zealand 773, you could be waiting well over an hour. Other times, it's been less than 20 mins. All I can suggest is to try and sit as far forward as you can to get off ahead of the other passengers. If you're using your 241 for a J ticket, go for upper deck near the front door, you'll deplane without having to wait for First Class.