This book is dreadful: here are the many reasons why:
The material is disorganised. The book is ostensibly about extra spatial dimensions. The concepts are introduced in the first few chapters then don't re-appear until the last few chapters. The Standard Model is introduced twice.
The explanations are poor and sometimes wrong. The section on the Pauli Principle is riddled with errors and omissions that should embarrass a good A-level chemistry student. The section on CP symmetry and CPT symmetry is so bad that I did not recognise these concepts for what they were until several chapters later. These concepts are not actually difficult to explain, even if it is hard to see why they should be true: In CP symmetry, all matter is swapped for it's antimatter equivalent and the directions left and right are reversed. When this is done, no difference can be detected between before and after the swap. This symmetry is known to work for all physical processes except those involving the weak nuclear force. In CPT symmetry, as well as swapping matter for antimatter and left for right, the direction of time is reversed. This symmetry was believed to hold for all circumstances - it could have happened five times since you started reading this review and you would never be able to tell the difference! However, very recent results have suggested that neutrinos and antinuetrinos may have different masses which would mean that CPT symmetry does not apply to them. This isn't a well established result yet, though. So, really, how hard was that to explain? Randall also offers the worst introduction to the fundamental mysteries of quantum mechanics I've ever read (and I've read quite a number).
Randall can't write: Additionally to giving bad explanations, Randall also gives us a very bad story at the beginning of each chapter. These stories have no literary merit and do not make understanding the forthcoming material any easier. They are like the dialogues from Godel, Escher, Bach by Hofstadter with all wit, literary merit and purpose removed, except they aren't dialogues, either.
Pop song wisdom: Each chapter begins with a quote from a pop song. These are not profound or witty. Many, many years ago I developed the principle, "Do not get your life wisdom from pop songs." One could also say, "Do not quote pop songs at the heads of chapters unless you want to look as if you've never read a book in your life."
Repetition: Using the same unclear explanation over and over again does not make a topic easier to understand. Since it was very difficult to understand Randall's explanations of concepts I am already familiar with repeating them isn't helpful.
Bloat: The new "physics" Randall wants to explain comes in the final two chapters of a long book which is full of digressions that are irrelevant to the main thrust. Weirdly the author includes every theoretical development of the last 20 years except the only one that has a firm experimental basis (i.e. neutrino oscillation, which I'm not going to explain here). Weirdly, this would have been useful, unlike the ones she does include, because the issue of "flavour mixing" comes up at one point. Again it took me some time to realise that this "flavour mixing" was something I knew about - neutrino oscillation!
Is there anything good about this book? Well, there's an explanation of why one theory of relativity is Special and the other is General that you won't find in many other places. Is that compensation for nearly 500p of tedious, repetitive and extremely speculative barely comprehensible explanations? No, it is not.
Stick to the maths, Lisa; you're good at maths.