This is the second study text that I bought - I mistakenly thought that the official text was available ONLY through the Home Office publication. In that belief, I bought both this text and a study guide with practice questions.
I found that the Study Guide and CD Rom by Henry Dillon (ISBN 095521596X; published by Red Squirrel) includes the full text from chapters 2 through 6 - the ones that are covered in the text - of this Home Office publication. In addition, the Henry Dillon book includes 10 practice tests in the book and a CD Rom that allows you to access online practice materials. I feel that the other book is much better value than this one.
It may seem like a minor point, but I also feel that the Henry Dillon book is also in a more convenient format. It's a smaller but thicker paperback compared to this Home Office publication, which is thin but A4 sized and harder to carry in your average handbag!
Overall, I don't feel that this Home Office publication is useful as a study guide and it doesn't offers much preparation for the test. Without sample questions, it is difficult to get a feel for how to treat the text - Should I memorize every fact? Do I need to know every date? The volume of information is actually quite large and the text fairly dense (every sentence is important), so without sample questions it could very easily become overwhelming.