This book had a lot of well organized information for understanding ETFs, what they are technically, what is involved in construction, maintenance, and trading them. It is definitely geared more towards the slightly above average individual trader. However, I did find explanations of mechanics interesting and helpful.
I found the interviews with a few of the major players in the industry at the end of the book very helpful as well. I particularly appreciated the question about short selling. Very insightful and telling of the distance between construction and trading.
Overall, I would recommend this book as an slightly better than entry into this seemingly straight forward product. I would say where it probably fell down the most was in the claim to discuss how to use these instruments as "hedges". Implicitly it seems obvious from an exposure standpoint; and in truth, the author does discuss some of the vagrancies between etfs. However, hedging is a bit more of an art; and in truth, would probably require another 300 pages to start to understand.