With the exception of JQ58 which ops SIN/DRW/CNS whereby transit pax remain airside everyone else arriving from JQ flights from Ho Chi Minh, Singapore and Bali (and coughet soon rumour has it) must clear customs in Darwin then go and drop their bag off at Jetstar check-in before going through security then upstairs again to board their onward flight to either MEL/SYD/BNE which has now become a domestic flight by now.
Now I'm assuming you get your boarding pass all the way to your final destination when checking in at your Asian board point so to avoid the grief of having to queue up after a long flight at a not so great time of the morning you could always consider travelling with carry on luggage only.
That way after clearing customs you would proceed upstairs immediately to the 1st floor where the boarding gates are. Qantas Club currently opens about 0500 and closes at 0730 (after departure of the last early morning Qantas Link flight to Alice and Perth) - they do not stay open especially for Jetstar flights so for example if you are arriving from Ho Chi Minh City at 0615 then continuing on to Sydney at 0845 you will have to leave Qantas Club at 0730.
If your arrival in Darwin happens to be on a Mon/Wed/Fri morning you will also have to contend with disembarking Garuda pax from Bali going through customs. It's not uncommon to have pax queued down the aisle of the plane because there is no room in the customs area to stand.
Then there's the matter of the single baggage carousel in the international arrivals hall that cannot fit baggage from 5 international flights at once.
Now I don't mean to rain on everyone's parade here by being a pessimist I am just telling you exactly how it is. I will however make a couple of suggestions on how you may be able to avoid any unnecessary waiting, queueing etc.
1. Try and get seating as far forward as possible on the aircraft so you can be one of the first off. You can reserve your seats at the time of reservation or anytime after by going on the web and displaying the seatmap and selecting your seats or if you can't call Jetstar and they should do it for you.
2. Prior to arrival make sure you complete your incoming arrival card (orange) that is usually given to you by the flight attendants sometime during the flight. You may be able to pick one up when you depart Oz also.
3. If you are getting Duty Free on arrival ensure it has been prepaid so all you need to do is literally grab it and go as JR Duty Free will have it packaged up waiting for you.
4. If you can travel with carry on baggage only you will thank yourself then you can exit customs immediately without waiting. I've seen people who've missed the next sector of their flight because they've been held up in customs (Ho Chi Minh/Sydney flight) so have been offloaded by Jetstar in Darwin as they weren't at the boarding gate in time.
5. If you are connecting to a Qantas flight at lunchtime I would seriously consider pre-booking a room from the night before at the Darwin Airport Resort. Being able to get to sleep while it's still dark not to mention sleeping in a proper bed does wonders to keep jetlag at bay. Maybe stay another night in Darwin and have a bit of a look around. You will definitely be in better shape by the time you get home. Believe me it's money well spent and you will thank yourselves for doing it.
By the way for those people who posted the Darwin Nightlife photos above, may I just say I have lived in both Sydney, Brisbane and Darwin and I would much rather be sitting on Mindil Beach or at the Trailer Boat Club in Darwin in the midst of winter enjoying a balmy 28 degree evening with a light breeze, fabulous sunset with a glass of bubbly in hand than a bitterly cold wind in Martin Place or the Queen St Mall down south in pitch darkness!
) seems to stop pretty early.
