Bryan Appleyard has an amusing post about irritating people who effectively set up office in Starbucks. (I like the punchline especially.) Can't say that I have ever witnessed this behaviour in Brisbane, but then I don't like Starbucks and rarely visit them.
As far as I can tell, most Australians think Starbucks coffee is not great. I am no great fan of the beverage, but I really like a medium size Very Vanilla Chiller from Gloria Jeans. The GJ franchise just seems a lot more relaxed and less pretentious than Starbucks, too.