I did the All of Oz tour in September 2009 and I have to say it was the best and most amazing tour I have EVER done!!! Although it was quite expensive, you get to see so much of the country and make friends for life. Everyone had such a laugh and the sights were really really beautiful, especially the east coast and the west coast. Also you get the chance to do stuff you would have never done before, like horse riding, diving, white water rafting and sky diving etc.
Personally I have REALLY brilliant memories, and my only regret at the time was having to come home again!! WELL WORTH the planning and saving to do it. Make sure you bring enough memory for your camera and insect repellant!!! We did get bitten in some of the hot Northern areas and bring enough sun cream, sounds obvious but most of us didn't quite realise how hot it would actually be until we got there. Just be willing to muck in and help out at all times with the cooking, cleaning etc you can't be lazy on this trip!! Have fun.