This is a varied collection of articles by just about every great modern science writer you can think of. The articles range in size from about 8 pages to as little as half a page, and each is preceded by a short, interesting introduction by Dawkins.
I read a lot of popular science books so inevitably there were a few items which I had already read, but it was nice to be reminded of them, such as Haldane's delightful poem which begins with the words "I wish I had the voice of Homer, to sing of rectal carcinoma!" The items vary considerably in difficulty - some could be understood by a child, others require concentration - and some topics were familiar to me, others were not, so although all the articles are good it is inevitable that the reader will enjoy some articles much more than others. They also vary considerably in subject matter - some are about what science has discovered, others about how scientists work, or the philosophy of science, or amusing anecdotes.
I think anyone interested in Science should get a lot out of the book, and I have been stimulated to seek out more writing by some of the authors. Highly recommended.