Valuable tips that you have to find for it ...

The book really gives valuable tips and tricks on how to, for example, the best essays based on how to structure the answers in the Speaking section and how to recognize false answers faster.
This valuable knowledge but you have to work its way out of a plethora of other information. Here, the authors should have some limit. Sometimes less is more. Still, I'm glad I bought the book and heeded the advice. The effort is worth it.

The difficulty of the exercises does not correspond to the real test. I have all the duties, especially in the "Reading" section, found to be too easy. Here it makes sense to use the "Official Guide to the TOEFL Test" of ETS to prepare. The company ETS is the maker of the TOEFL and used to exercise real, discarded test questions.

Both books together were the perfect preparation for the test for me. My result is in all four test sections at the top. That I owe my estimation also the tips and tricks from this book.