Having read the review by Dr Greenthumb I was initially put off of buying this book. However, when it appeared at a really competitive price I decided to buy it on the off chance that it might have some useful information in it. I am really glad that I did, since it arrived I have constantly been dipping into it - and visiting friends have also became engrossed in it!
This is a very informative book, and a thing of beauty in its own right. If photography is a hobby to you (as it is to me), you will find loads of useful information inside this book which is presented in an easy to digest manner. On top of this you will have the added benefit of owning a top quality publication full of beautiful photography.
If you're looking for a field guide, forget it! I haven't actually weighed the book but it is certainly one of the heaviest in my collection. You wouldn't even be able to describe it as a good bed-time read because, if this was laying on your legs for any length of time, it would probably cut off their circulation (lol).
I would highly recommend this book - and I think that my friends would too.