I bought this book a few weeks ago to prepare for my theory test, which I passed on Friday with 50/50 for my theory. I really think that if I hadn't bought this book, I wouldn't have achieved such a mark- it really is money well spent. The format is clear, concise and exceptionally easy to use. The book also includes the recently added 'case studies', advice under each answer to give you more confidence and the complete Highway Code. I also had a driving theory CD, but I really believe that this book enabled me to pass the exam.
If you are preparing for your test, I thoroughly recommend this book. You'll be glad you've had it after you pass with flying colours!