i found this book brilliant. It had good detail, enough by far but not too much. It was really suited to exam syllabuses so you dont have to learn loads that is basically background waffle and not useful to Alevel. It clearly shows you what you need to learn to get A01 marks, AO2 marks and A03 marks so you cant go wrong when you get to the exam, you've got everything you need.
Its also got practice questions and answers, and is set out in an easy to read layout with bright colours and pictures, as well as a revision mindmap all ready for you at the end of each section!
I found it perfect basically! I got an A grade :) If you're aiming for A*'s then you may need a little more detail than this book offers, but for the majority of people its got everything.