This book is superb.
I do own, the Business Analysis book as well and deem them both very useful. In the day to day throws of a BA this book will definitely aid you. In fact, I'd say that a lot of the techniques are not exclusive to the role of a BA, I can imagine a lot of managers (all levels) would find this book a great resource from which to make a start on understanding where they are, where they want to go and how they might get there.
For some techniques I feel the book is only a starting place for your knowledge (the authors recognise this) however what I find of most value is a.) there a specific techniques to use and b.) when and where they are best applied.
I now have no excuses not to do a good job as a BA....damn.