Thanks guys,
There's been minimal interest in this topic, which is a good thing. It means that overall there really is no difference between the available fuels. A few people have their personal favourites, but overall there are no horror stories.
I've done a fair bit of research into this, being my first diesel car. I've managed to come up with the following -
-Overall Australia has a poorer (but improving) quality of diesel fuel compared to other parts of the world.
-Cheaper fuels such as Safeway/Caltex have a higher sulphur content, which is environmentally bad.
-The 'Ultimate' branded fuels have a lower sulphur content, which can lead to engine damage in the right(wrong) circumstances.
-If you fill up from the servo nearest to you at the time you will end up with the best blend in your tank!
Cheers