This book is exactly what its title says: a quick introduction to ASP.NET MVC. A natural implication is that it cannot cover that much material, and it seems Maarten went for breadth instead of depth.
In my opinion, when a book chooses to be a “quick guide”, it should focus more on showing the preferred ways to do stuff. Instead, this book seems to have too much ViewData["stuff"] = fluff going on. Why bother wasting pages showing all the tedious, error-prone, hard-to-maintain ways to do stuff when there is so little space?
If I were to author a book on ASP.NET MVC, I would focus on explaining ASP.NET MVC from the extensibility points and out. For example, System.Web.Mvc.Controller is just one way to implement the IController interface, and so on. I think that would provide a much more wholistic image of the framework, and the extensibility points is where ASP.NET MVC shines. I don’t think Maarten’s book really shows where the framework shines.
I enjoyed the chapter on using existing ASP.NET features though, and, not being an ASP.NET guy at all, I think I learned some stuff there.
My conclusion is that this book is absolutely for beginners, and that the code samples in the book should not be taken literally, because almost none of them are examples on what the community considers best practice.