I live 65km's S/E of Albury and my opinion,for what it's worth is to hold off till the very last minute before switching over.
I have a Samsung A501 and whilst I get good coverage near Albury as soon as I get about 15k's out I start having call dropouts yet when I get 20 k's out I get good coverage again,Telstra say that it's due to not having enough Next G base stations enabled at the moment and that they are rolling out more of them all the time.
There is also the issue of what incentives Telstra will give you to switch over,I'm sure you will find that come January when they switch off CDMA they will be falling over themselves to get you to switch.