I've discussed some of the arguments about the AV referendum, but not really drawn a conclusion (beyond "whatever")
The main valid argument for AV is that it isn't as sensitive as FPTP to which candidate people think is going to win. It may get rid of the truly inane feature that I reported on at the last general election, where the parties argued more about who was likely to win than about who ought to win.
A second valid argument for AV is that it encourages the expression of non-mainstream views, by not penalising voters for unpopular parties. It doesn't actually give unpopular parties any more representation, as PR does, but it gives them more visibility.
The main valid argument against AV is that it is likely to produce centrist coalitions, whatever the changes in views of the voters.
Putting the three points together, I have to be in favour. In my theory, the value of democracy is that it has perceived legitimacy, reducing the amount that the ruling establishment hsa to do to protect itself. The one anti argument actually helps in this regard, as it makes the establishment even more secure.
However, the pro arguments are still applicable, as it is valuable to make the unconventional more visible, as that will aid thinking about what we should do when and if the current establishment does fail.