From my understanding, AV is a system which is like FPTP in delivering a single winner and keeping the link with constituencies, but asks voters to rank candidates rather than pick a single preference. Second and third preferences are shared out until one candidate gets more than 50% of the vote.

So it's not that much of a change from FPTP, but I haven't quite sorted out to my satisfaction whether the horse-trading that will result will be positive or not, and whether I really want to lose FPTP's capacity to thoroughly spank a party and chuck it out of government. I think that's an unsung feature of FPTP.