I generally only care about the food. Things like atmosphere matter maybe just a little. With that said, I think Niwatei is just an OK restaurant. This stuff is expensive. It seems that any restaurant that can establish itself as authentically Japanese (as opposed to Chinese) will be able to charge a ridiculous premium. This sentence is very true for the whole J-Town. Things are outrageously expensive and this seems solely because the place is run by Japanese people (and that their products are imported from Japan of course).
The food tastes ok. I think Ramen is one of the most over-glorified foods out there. I've tried other Ramen places like Ajisen and Kenzo and I think the quality is not noticeably better than either of these places, despite being owned by Japanese. The portion they serve is definitely not worth the price tag. Your ramen only comes with 2 slices of pork. If you want more,they charge you a whooping $2.5 for just 2 more pieces. It's not like the pieces are large either. This is Canada...when you add tips and tax, it's quite a bit. They have non-ramen things like curry (made with powder of course) and desert. These are even more overpriced than their ramen.
I had Ramen in Japan and I really don't understand the ramen hype in Toronto. New ramen places have popped up in moderate numbers this year. I think it's good business. Ramen is not particularly costly to make, yet it fetches a good price. I've been to Ramen places in Japan where they literally mass produce the soup and noodles and just scoop it out for you once you buy a ticket from the machine.
The only reason to try out all these Ramen places is to join the chic cultural bandwagon. So unless you're dying to be served by Japanese waitresses (they are not that cute by the way), I don't think it's a place you should frequently visit. I'd go once just so you can experience one of the few Japanese restaurants owned by Japanese people. You're basically paying a premium to be served by real Japanese people. Think about that for a minute.