First off, I'm really glad that this book is in my collection, and this is not a book I'd recommend to a beginner. This book covers good ground, but does not waste time hashing over the basics. I'd recommend having a solid comfort level with interpretations of single cards before starting in on this book.
Starting with the negative side, I didn't agree with many of the card interpretations. They were generally simplistic, however it may be that the author intended it that way in order to better illustrate the concepts that she was trying to convey. Many of the combinations are also simplistic due perhaps to the same principle. The author's approach is to assign a shortlist of keywords to each card, then read them like flashcards. If 4 Staffs is "Peaceful" and 6 Cups is "Often", the two cards together mean "Peaceful Often". Although my own experience is admittedly limited, I do not personally know of anyone that reads so literally.
On the positive side, the author's oversimplification freed me up to not overcomplicate relationships between the cards. While I do feel that the specific examples are oversimplistic, I also think that was useful to break down my fear of allowing it to just be simple. I haven't found that I've directly used the lessons from this book, but it has definately had an influence on the way I link cards together.
One wonderful thing about this book is that the focus on combinations means that it can print repetitive combinations for certain sets. Such as (example is from my head, not book): Ace Wands/Two Wands, Ace Wands/Three Wands, Ace Wands/Four Wands, etc. It clearly can't cover every combination that exists, but it covers enough to allow you to exrapolate your own beyond a certain point. It also makes for easy light reading -- would be easy to read a few pages here and there when you have the time.
I feel that this book is generally most useful for those who have a good feel for what the cards mean on their own, but aren't as comfortable reading them together or in spreads.