The main reason that Pacific live rock is prefered that most of the corals and livestock we keep in our tanks comes from indopacific reef systems. The live rock from these regions has a more accurate biome for the organisms we keep. Also due to the way it is packaged and shipped there are generally far less undesirable hitchhiker's. Florida rock usually ship's submerged so the hitchhikers stay in the rock. Since Pacific rock ship's wrapped in wet paper the undesirables usually will jump out of the rock and go to the bottom of the box looking for water. Florida rock is usually quarried rock dropped in the ocean were as Pacific rock is usually actual reef rock. Quarried and man made rock is more dense and has less porosity for microorganisms to populate. There are many reasons why pacific rock is better too bad it is so hard to come by.
The best deals I have seen on the Aussie rock come from Live Rock n' Reef. Pretty pricey stuff though. They also offer some man made Fiji rock for a competitive price but those rocks are basicaly cement that has been submerged for a year or 2. IMO the Fiji man made may be useful in seeding a new tank though I wouldn't want to use them beyond that. They are not the same legendary Walt Smith Fiji Rocks of years past.
The best deals I have seen on the Aussie rock come from Live Rock n' Reef. Pretty pricey stuff though. They also offer some man made Fiji rock for a competitive price but those rocks are basicaly cement that has been submerged for a year or 2. IMO the Fiji man made may be useful in seeding a new tank though I wouldn't want to use them beyond that. They are not the same legendary Walt Smith Fiji Rocks of years past.