My prior was based on my initial reading of the book; I came away thoroughly disappointed, and quite certain that the book would be useless due to its offensive nature (not to mention the careless way Dawkins discloses his biases, such as his feud with his ex-wife), and probably damage Dawkin's reputation to boot. I've since updated on the responses I have encountered, which were only sporadically positive among atheists and even more sparsely positive among agnostics, and universally negative among the religious.