I picked up this book for two reasons. I wanted to learn what derivatives are, and I wanted to learn about the math around them. At first glance, in the bookstore, it looked like this book would meet my needs. Now, I have to say that this the first book I ever read about derivatives and have nothing to compare it against.
The first few chapters do a good job explaining what derivatives are and how they are used, though I found the chapter on swaps somewhat confusing despite reading that chapter twice. Additionally, I found the conversational nature of his writing, and the frequent drift into sidebar discussions, quite distracting. The chapters on pricing derivatives were worse.
In the pricing chapters I found the basic explanations ok, but there are a number of errors and typos that make those chapters confusing. The author also changes terminology occasionally and that is a little confusing. At one point I emailed the author in order to clear up my confusion, and he directed me to the errata list on his web site. I found I had to read the section on the Black-Scholes model backwards because the second half of that section gave me what I needed to understand the first half.
I found the explanation of the math most frustrating. The equations use symbols to mean something different than I would expect based on how those symbols are used in math and science texts. For example, he uses Greek delta to mean "amount of" instead of "change in." Now, perhaps this is the standard usage in the financial field, but that isn't explained very well. In many cases the author does not explain what the terms in the equations are, where their values come from, or what they are measuring. More explanation here would go a long way in helping the reader to understand the math better.
In summary, like my headline says, the book is ok, but not that great. Perhaps other books on the subject are very bad, but I would advise reviewing other texts for a bit before buying this one.