Condo advertisments are no different than ads for Big Macs or beer. Its marketing. Every ad does as much as possible (within legal limits) to make its product seem as appealing as possible. Toronto condo ads are no different than ads in any other major North American city.
Renderings can be good for offering one perspective as too how the building will look. But renderings will always be somewhat misleading. It is hard to find a program that can accurately render every material in 100% detail and to the exact specifications of the product that is actually being used. Ad that many companies just want something that will catch peoples eye and are not going to be too concerned with accuracy and you can ensure that most every rendering, anywhere, will be misleading.
In the end, if you want to know how a building will actually turn out, dont trust renderings, just as you wouldnt trust a McDonalds commercial to determine how your Big Mac will actually look when you get it. The best way to understand how a building will turn out is go through city documents and using elevations, research on the specific materials being used, manufacturer information, and a little imagination, you should be able to determine how it will turn out. Also just look at built examples of what the company has done before, which can offer a strong insight into the quality and construction techniques of their projects.