If you are looking for one book to introduce you to the wide and varied world of classical music with all its eccentric characters, then look no further. The top 50 list he produces is a subjective one, but the author is quite clear about this and offers many alternatives as well as giving a comprehensive summary of many he did not include in the Big 50.
The most useful aspect of this book, in my opinion, is the list of suggested material for each composer and the author's comments on that material. Goulding does an excellent job in maintaining a balance between his own musical tastes, those of the musical establishment and enthusiasts for particular composers. He uses an anecdotal writing style that makes the bulk of the book more easily digestable and entertaining. In summary, this is a book full of personality that manages to be jam packed full of information nonetheless.