AV works well down under...
I'd just like to say that the AV system we have in Australia works pretty well. Usually very few complaints, maybe the odd recount when the voting comes down to a few hundred votes, but otherwise ive never heard to many complaints.
One thing i would certainly suggest be added to the law though (from experience with Australian AV) is the preference deals that the parties make be published ahead of the election, so people know that if they are voting for party A and party A doesnt look like getting into the top two, then you know that your vote will be going to party B and not party C.
(i.e. your in an electorate which is always out of Labour and the Tories. But you want to vote Lib Dem, just in case. But if you know in advance that your Lib Dem vote (if Lib Dems dont get enough) will go to the Tories and your massively anti-Tory, you may choose to vote directly for Labour, so that your vote doesnt end up going to your most despised party. (Yes i know this example makes no sense on current political bias but its an explanation!).
Either that or make people choose there order for all candidates (in Aus, you have the choice of numbering all of the candidates for your electorate in your own preferences or choosing the party of your choice and relying on there predetermined preferences to make your vote count).