I think before you decide on either Adelaide or Brisbane you should look at what your long term goals are from property and see which locaion will be the better fit.
There are a number of people in the industry who feel Adelaide is the next hot spot and there are some very good reasons for this. South Australia is also resources rich, like Western Australia, it's biggest resource being Uranium. There is a lot of stuff in the pipeline for the Roxby Downs area that will feed property prices through out South Australia. many feel that over the next 5 years Adelaide can averaage over 10%pa.
The South Eastern Qld Golden triangle will always be an exceptional are to invest in but shouldn't be seen to be the only spot in Qld to invest in. There is another triangle in Qld that has shown consitent growth over a number of years and it is fueled by a number of industries. The area from Cairns, Townsville, Airlie Beach and out to Mt Isa is yet another Qld area showing exceptional returns for your money and you can access brand new, to renovate or what ever you want.

Myself, I am watching a couple of area's around Adelaide and Far North Qld, I am talking to developers to see what they have in the pipeline for the area's and then making my decision.

Regards