Shelley takes on the unenviable task of summarizing primarily western Church history into an easily swallowed dose. He pretty much succeeds, but the nature of the task requires summaries and broad strokes that sometimes seem prone to inaccurate interpretations. On the one hand, it is a manageable read and not a bad introduction for someone not used to reading history. On the other hand, it does not go into enough detail or specific source citations to make a good reference.
I read this book as a textbook to a class and found it to be both enjoyable and informative. Although other multivolume sets do a bit better job at digging deeper into the various aspects of church history, it would be difficult to find a single volume that does a better job than this. Shelley has a way of making the history fit together in a way that other authors simply cannot do. My only criticism of the book was that the latest additions to this work seem to be tacked on at the end and they seem to lack the polish that the other chapters had. It is a great book and I have recommended it to others who want a single volume work that is enjoyable to read yet informative.