The head first approach depends on a lot of images, since an image says more than a thousand words. It also depends on repeating the information in different styles, and dialogue like text.
Even though this might seem as if it's a very simple approach, but the result is amazing. The book is fun to read, full of information, and yet very simple. Never thought I would love to study that much again.
Now enough about the head first approach, and into the book itself. The book is very informative, and covers nearly everything in the exam. Very few subjects were not covered, but most of them are covered in the questions at the end of each chapter, with a reference to the place of the information in the specs.
Few mistakes are there (like any book in the market), but most of them are spelling mistakes. The O’Reilly website has a great errata page covering every single mistake in the book (even spelling and grammar mistakes).
A lot of topics covered in the book do not even appear in other books, and a lot of those come in the exam. I studied from that book, and got 94% in the exam. Great book, and really fun to read.
Buy the book from amazon.com