The slightly more expensive Sony ebook reader only stores 350 books, you can't a card to expand the memory, and books purchased from the site are charged to Canadians in USD.
Not a superior product IMO.
Same with the Kindle. Not all ebooks available for Kindle in the US are available to Canadians, because of publishing rights and so on.
For me Kobo was the logical choice. I've already purchased 5 ebooks for it, the prices are cheaper than paperbacks, and I've already purchased my second Kobo as a birthday present for my daughter.