On my first run through the practise exam that came with the book, I needed half the time and scored 93%. Sitting through the real exam I spent close to the alloted time and scored 85%. I.e., the real exam was more difficult than the impression the book gave me. I can also agree with other reviewers that there are factual errors to watch out for. If something doesn't make sense, look it up elsewhere!
But in all fairness, it was also quite helpful. I liked the exam-hints as well as the review bullets and test questions at the end of every chapter. More code exercises would have been great.