I think that a lot of the criticism that this book receives is due to the fact that people do not pay attention to the title. This is a language reference, not a tutorial. As a reference, it's wonderful. Due to it's dictionary-like structure, you'll be greatly disappointed if you expect to learn C# from scratch from this book.
The entries are both clear and informative. The nice thing about this book is that it doesn't get carried away with exposition. It tells you exactly what you need to know and nothing more. Also, the examples are generally short, but they are clear and do a good job at illustrating the concepts. As a reference, which is all that this book is, I could not ask for more.