Reading this book was disappointing but that is not entirely the fault of the author. It should be noted popularizer of his talents when he addresses technical concepts such as renormalization and gauge invariance. However, the sections on branes and dualities appear confused and incomplete to the reader. In fact, the main drawback of this book is ... about it! The author highlights against his sore string theory: no testable predictions by experience, unfinished theory ...
I recommend on this subject the following book: No more physical! : The Failure of String Theory