The best part of this restaurant, in my opinion, is meant to be the view of the Toronto city core that you get from above the regular observation deck. And the view is breath-taking, especially at night.
The service was very good, and the food was better than average. The portions more than justify the prices that are charged (on average the main course for dinner is around $40 to $50, but you do get a significant amount of food for the price). Given that you do get complimentary access to both the lookout and glass floor levels of the CN Tower with your meal ($32 per ticket for general admission), it is definitely worthwhile.
Yes, it is a little gimmicky. Yes, you're unlikely to come back again and again and again given the price point and the food that falls short of being stellar. But the view of the city at night? Worth every penny.