I find it hilarious each year when the ATO publish the 'cost' of negative gearing, which is something along the lines of a few billion in net income tax deductions and reduced CGT.
Nobody ever mentions the land tax and stamp duty that investors pay! The fact that they're paid to the state and income tax is federal is irrelevant, as Canberra bankrolls the states in any case.
My very simple way of looking at it is that the average stamp duty in Melbourne is about $20k, on a 500k investment property. Assuming the investor pays tax at 31.5%, they'd need deductions of $63,500 before they've made back the stamp duty alone.
As for concessional CGT rates, investment property enjoys exactly the same CGT regime as any other asset class such as shares.
When I moved to Australia 5 years ago I was really surprised by negative gearing as I believe it distorts the housing marked considerably. However, it's a bit like driving on the left side of the road, whether you like it ir not, we're stuck with it, as changing it now would have too big a structural impact on the economy....and no pollie is stupid enough to get on the wrong side of close to 1m landlords!
Cheers
Jonathon