This book looks like a bestseller buy it is not as easy to grasp by the average read as it might seem at first sight. It is extermelly long, the number of topics treated is overhelming and it is full of formulas. The author claims you can skip these formulas and you will still benfit from the insights of its pages. However I am not so sure about this statement. Without the formulas you miss much of the value of the book and it becomes increasingly difficult to understand.
It will require you a special mental predisposition to finish the book and in its desire to cover everything, the author makes what in my opinion are unnecesary incursions into complex mathematics to explaian even simple concepts.
Nevertheles, I like Penrose's sometimes revolutionary proposals and it is refresheing to find sombody who dares to oppose the mainstream ideas from time to time. This reason alone makes the book worthwhile.