I don't think that legitimacy comes down to an option like that. It's the entire process that matters.
If you have a process that has a referendum, then that would be one way of thinking about legitimacy, but as I said in my remarks, it's not required for legitimacy. My concern around a referendum is that it's not politically neutral, because it tends to favour the status quo, as we've seen in the provincial efforts at electoral reform.
There are a number of reasons that referendums tend usually to fail in that way. Given that there is a tendency toward the status quo, I do not think that a referendum is a requirement. It's usually favoured by people who like the status quo and by political parties that prefer to see the first-past-the-post system remain.