Even though I am not a believer, and agree with most of Dawkin's points, I found the book only "so-so". Why? Well, it's a case of "the lady doth protest too much".
Dawkins is so angry with religion and God that he overstates his case to the point of nausea. He dismisses all concepts of God as nonsense: and Buddhism, a religion without a God, he says "cannot be called a religion but an ethical system of philosophy". He reduces all religions to reflections of the monotheistic one he's attacking, then uses the most extreme examples of the same to debunk it. Talk about straw men.
The author throws away a chance to present his argument constructively, and uses the same polemic of his opponents. He must have alienated a lot of open thinkers in the process.
Read it if you hate God and would like to listen to someone ranting against Him. Otherwise, you might be a tad disappointed.