Yes, I own DVC at a few different resorts and have found it to be great, even though I have only actually used it once so far.
As far as whether it is worth it for Aussies, it basically depends on how often you travel to DVC locations, which now include Oahu and Grand Californian as well as WDW, as it is generally not worth using them for the other options. The general rule is that if you travel at least every three years it can work.