I don't know about the country as a whole but around the Toronto area I think the largest noticeable category of vehicle is the van. If it's not, it cetainly comprises a large amount of vehicles. Although we use one of the great little small cars that are available now, for most of our journeys; we still keep a van for low milage use and occasional large load. Good for camping trips and moving kids from one appartment to another.
I can't comment on the reliability or quality of the Nissan and you do not see many. Maybe pricewise there is a problem. It seems to be very long though and the swoop sides do not appeal to me. I like the completely dissappearing seats in other marques but notice short versions are now history. Thats a shame.
Siennas and Odysseys are highly priced (OVER priced atually), and they are very popular (but less so than the domestics, probably related to price).