I have tried 3 Ramen places in Toronto: Niwatei, Ajisen, and Kenzo. Kenzo is the winner of these 3 in my opinion. Their atmosphere is better than Ajisen's by miles. They may not have the authentic Japanese feel of Niwatei, but the place looks modern and inviting.
The fact that complementary tea is not served is something I'd generally frown on. However, Kenzo serves a special green tea. It's a stronger version of what you normally get at other places. This green tea is so good that I had forgiven their lack of free tea. I tried their iced version of the green tea. It's just as awesome and this is the kind of thing I'm willing to pay $$$ for.
Taste wise, I think Kenzo is surprisingly better than Niwatei. I find Niwatei's to be amazingly overpriced and not as delicious. Kenzo's soup has a stronger flavor that is closer to what I tasted in Japan. Kenzo's portion is also better than Niwatei's. Don't even get me started on Ajisen's food.
The only reason it doesn't get 5 stars is because it's still kind of expensive and the service is not on par with what you get in Japan. If someone opens a ramen shop with really delicious ramen, at reasonable prices, and complemented by cute waitresses like how it is in Japan, then I'd give it a 5 star rating. I'm kind of using restaurants in Japan as a benchmark for ramen shops. Realistically, I think we'll never get that in Canada.