I bought this for my Step 1 review and love it. The book is broken up into sections, with several cases for each organ system. The case gives a basic vignette of the presentation of a patient, and then below it is information on what the disease is, what signs and symptoms you would see, how you would treat it, etc. It is a great way to tie in lots of information.
It definately is what you need in addition to the usual First Aid for Step 1 book, because that book is sadly lacking in detail on many diseases and drugs. This book fills in what they miss, and presents it in a way that mirrors what you will see in questions and on the real exam. I find it a great way to review what I've read in FA, learn how it would present in a patient, and make my knowledge more solid.