The other thing that so clearly marks Australian democracy from American is that our Parliament doesn't allow filibustering. There are set limits on times for speeches which generally mean that people have to stick to the topic.
I think some people think filibustering is easier than it really is. First of all, it can only occur in the Senate; the House of Representatives, being a much larger body (435 vs 100 members) always has time limits on speeches. You can't filibuster there.
Even in the Senate, a cloture vote can be taken to cut off debate. This used to require a supermajority of 2/3 of the Senators present; since 1975 it requires 3/5 (60%) of
all Senators -- whether or not they are present and voting. In practice, this has made cloture easier and filibustering somewhat more difficult. Now filibustering tends to occur only when one party has only a slight majority in the Senate, which has often been the case in recent years.
I think the American system has bigger problems than filibustering. At times it can even be a good thing by serving as a check on the tyranny of the majority, though it has often been the reverse such as when many Southern Senators filibustered the Civil Rights acts of the 1960s.
The main difference between the American government and most other western democracies is our President. Rather than being the leader of the majority party in the legislature, he's elected independently and runs a completely separate Executive branch of government. All three branches (Legislative, Executive and Judicial) are in theory co-equal and separate, each with unique powers over the others and limits on its own power. While the Congress can impeach and remove the President (or any other federal officer) from office, it is nothing like dissolving Parliament and calling for elections. It is a much more difficult, solemn and painful process that, while tried twice (Andrew Johnson in 1868 and Bill Clinton in 1998) has never actually succeeded in removing a President. (Nixon resigned in 1974 rather than face inevitable impeachment.)
More important than filibustering, I think, is the President's veto power. He can veto any bill sent to him, and his veto can be overridden only by a 2/3 vote of
both houses of Congress. Because Congress has been so divided in recent years, veto overrides have become extremely difficult and this hands considerable power to whoever happens to be President at the time -- already a very powerful office compared to most Prime Ministerships.
Since FDR was elected four times in a row, the US Constitution was amended to implement term limits for the President; no one can now be elected more than twice. (In theory one could still serve nearly 12 years if first elected as Vice President, succeeds to the Presidency on the death or resignation of the incumbent, and is then elected President twice in his or her own right.) So this means that most Presidents spend their first 4-year term trying to get re-elected. Only if they succeed do they have the option of conducting a second term without having to worry about another election (though they are still very concerned with getting members of their own party into Congress, of course.) It is always interesting to see whether a President makes truly major policy changes in a second term; usually it doesn't happen, but it could.