I won't comment specifically on P.E.I., because I'd have to study it soberly before I would form an opinion.
There are many different forms of multiple preference ballots. There are forms in which you can do that with proportional representation, PR light or the full PR, or a single transferable ballot. Many people have talked about AV, because it's simple; it's the minimal adaptation to our existing system.
At page 56, or page 61 en français, there's a quote from Winston Churchill about that, which I have to admit I'm rather attracted to, which is—let me put it gently—not a great idea. The problem with AV, as Churchill says, is that it puts the most weight on the most worthless ballots of the least popular parties.
Why does the second choice of a small party count more than everybody else's second choice? It doesn't actually keep proportionality, and it has a lot of other problems, but I can't get past that problem.
In terms of the language of “plebiscite” versus “referendum”, I think technically one is binding and one is not, but to me it's not a legal question anyway. Legally you can do a lot of stuff without putting it to a popular vote. I see, since the Charlottetown Accord round, that there is now a morality of consent in Canada such that, if you're going to make big changes, the question should be put directly to the people in a vote.
May I say one other thing, quickly?