The functional difference between free speech in Australia and the United States isn't that strong. On the idealistic part of the spectrum, the US does win, but in terms of how it affects your life, they're pretty comparable. It is interesting to note that Australia is consistently rated superior to the US on the Press Freedom Index, and both are outscored by a passel of European countries.
http://en.rsf.org/press-freedom-index-2013,1054.html