My view is that duality is an example of cultural autonomy. Autonomy does not mean separation, but the power to handle one's own affairs. New Brunswick duality system recognizes that both communities are culturally autonomous. Each administers its own institutions.
I don't think we can expect a population that has only 5% francophones would have the same duality experience as New Brunswick, where 70% to 74% of the population live in regions where francophones are in the majority. That's probably a factor that explains why the system works in New Brunswick.
I believe that the concept is a good one. It has been shown repeatedly that bilingual institutions don't work. In 1963, for example, if we had followed the bilingual model of the University of Ottawa when Université de Moncton was established, the latter would not have contributed as much to the vitality of the minority. That's why I don't believe it all in bilingual systems.
Cultural autonomy needs to be adapted to the vitality of each community. I believe that's the best option.