The book gives a very good overall picture about an SAP project. It covers a lot of topics, and is excellent for people who are e.g. just coming from the SAP Academy, where many of the topics have just barely been mentioned.
For people with experience from at least 1 project, the book does not have so much to offer, because of the lack of details. Still, the chapter about people related issues and change management is definitely worth reading. Also the long lists of typical problems and success factors in projects are excellent - everyone in a project can use those lists every once in a while to check how well the project is going, and what kind of risks there might be.
So, for beginners, this is a very good and well balanced starting point. For people with more experience and who are looking for detailed technical information, this is not the book to read. But for those who want to improve their overall project management knowledge, the book is very well worth reading.