I lean towards a referendum for an eventual model. I realize that's answering in the abstract and without any consideration of what might happen between today and some point later on in the process. I do so for a couple of reasons, one is a question of democratic legitimacy.
The New Zealanders did it in a country that is smaller and much less complex than Canada. They did it twice, in fact, as my colleague has said. Three provinces did it, and New Brunswick would have done it if there hadn't been a change in government. Premier Lord had committed to putting the model recommended by the commission to a vote, but that didn't ever occur.
I want to respond just very quickly to the view that a referendum is an automatic way of killing reform. First of all, I find it's rather cynical. I think it sets aside the democratic legitimacy arguments and reduces everything to a question of political tactics, but more importantly, there are important counter-examples. In British Columbia, 57% voted in favour of reform. It didn't happen, because the government had said it had to have a 60% majority. It would have happened in a simple majority system.
In New Zealand in the first referendum, 85% of voters rejected first past the post. Then they had a second question. They had to choose from four options, and 70% chose mixed member proportional, which was the system that was eventually implemented in New Zealand.