The first thing that needs to be said about this book is that it is NOT a book about keeping cichlids in aquariums. I think that is a misconception some people may get since cichlids are such popular aquarium subjects. If you're looking for information on cichlids in the aquarium, you need to hunt down books by Paul Loiselle or Ad Konings. This is a book about evolutionary science.
The cichlids are really the animal darlings of the evolution field in the same sense that the Galapagos Islands are the geographical Mecca. This book focuses on cichlids from the African Great Lakes: Malawi., Victoria, and Tanganyika. The populations in these lakes have been isolated and thus present a wonderful living experiment in evolution and speciation. The New World members of Cichlidae aren't forgotten - there's plenty of examples from them too.
The text doesn't delve too deeply into scientific theory. It's still a relatively easy read for the layperson. Its aim is to explain why the cichlids fascinate biologists and evolutionists - without getting overly technical. It achieves that goal admirably.
The bibliography is worth the cover price. There are 23 pages of small-print references and a numerical guide to citations by chapter.
If you're an aquarist with an interest in the science behind the fish, a scientist with little experience with fish or evolution, or a "normal" person wondering what all the fuss is about, this is a good choice.