ContactMeNow,
As posted in the other thread, and followed in this thread, outside of metropolitan and regional areas, you need to think about which carrier.
You also need to understand that, under the Federally funded TSI plan, virtually every community of 500 or more had a funded CDMA cell installed.
3G and Next G are in fact "Wireless CDMA", 2100 Mhz and 850 Mhz respectively.
Every CDMA cell now has a Next G 850 WCDMA capability.
What this means is that while your GSM phone will work in KNX, Broome, Wyndham etc,
get 30 kms out of town and you will have nearly always nothing.
If you have CDMA or Next G, you'll still be in business a lot further out, and if you spend the day in Kalumburu, Port Keats
or any of the dozens of indigenous communities you will have a phone that works on the ground while you spend a few hours in those communities.
Optus can fix you up with CDMA, piggybacking off the Telstra network,
however, if you're still up there next year when Telstra shuts down the CDMA network, goodbye Optus, hello Telstra Next G.
(yes, Telstra will make it attractive for you to swap your CDMA for Next G)
Telstra will not be providing its competitors access to their Next G infrastructure.
right now you have several choices, Optus CDMA, Telstra CDMA, or Telstra Next G.
Right now you do not have much choice in handsets with Next G.
A good compromise is the Motorola Maxx V6, it can use 850 WCDMA (Next G), 1800 GSM, and 2100 WCDMA (3G).
If you dont go CDMA / Next G, your city phone will be just an expensive alarm clock and pocket game machine for a lot of the time you're out of town.
If you go Next G, the sim card will be backward compatable with your existing GSM / 3G phone, but not vice versa.
Hope you've found enough explanations on this thread, practical and technical, to make your own final assessment.