Is it a good book? Yes it is. Very informative, however, very speculative as well. I would not call it a scientific book, as it is not. Do not get me wrong I am an Atheist and an Evolutionist, but the book falls short in a persuasive argument, as to establish what it claims. In its style it is not any different than for example "The signature in the cell" by Stephen Meyer, which in a sense is a shame, as the evolution as a science stands on a very firm ground.
The shortcoming of the book, in my opinion, is an attempt to interpret the Evolution, and specifically the role of gene, in a very peculiar way, Dawkins way, And for that Dawkins offers, lots of analogies, lots of interpretations, lots of speculations, very little scientific evidence to support his claims.
In saying that, there is still a great deal of information that is great and useful, as well as it is well written, which is typical of Dawkins.
I suppose one needs to judge the book by what it is: it is a popular book written for wide audiences, and as such might carry the weight for uninformed or partially informed.
A view which is not shared by all Evolutionary Biologists.