I've been to all of Australia's mainland capitals (sorry, Hobart). I've lived for long periods in Darwin, Sydney and Perth. I prefer Melbourne to Sydney based on the time I've spent in each. Melbourne seemed a bit more cosmopolitan, the people a bit less artificial. I'd rather live in Perth than either, but the startup scene here is quite anaemic. You can round up some geologists and raise tens of millions to do some…
Melbourne seemed a bit more cosmopolitan I was recently in Sydney and Melbourne, and you're probably about right. I don't know how to say it, but Sydney seems very, ahem white and very English.
This map gives a humorous account of Sydney's layout: http://i.imgur.com/gOxZP.jpg