This is about as comprehensive as it gets at this price. I know of no other book that presents the most common readings in meta-ethics, the history of ethics, moral language, normative ethical theories, and applied ethics. This gives the book a great deal of versatility for various focuses in introductory ethics courses.
Unlike many books of its kind, this book contains few things that are available in the public domain. Even for writings that are several hundred years old (or older) this collection tends to consist of scholarly editions of the text, which are not themselves in the public domain. Considering the relatively low cost of this book, that is a noteworthy fact. After all, it's irritating as a student to buy an expensive anthology which is 30-50% available for free online.
Another reviewer expressed dissatisfaction with the translations selected. All translators must wrestle with balancing accessibility with accuracy, and the results are not likely to be satisfactory to everyone. I can't say anything specifically about the Epicurus translations, but the works I'm more familiar with select (to my mind) acceptable translations. For example, the Aristotle is the Ross translation as revised by Ackrill and Urmson, which is not as good as the Irwin translation, but is better than the public domain Ross translation. The Kant readings are the Gregor translation, which is not public domain, and is generally considered the scholarly standard for that work. The Plato seems all to be Gallop translations, which are reasonably well-thought of and use more modern language than the Jowett. In general, for reasons that make economic sense, since this is an Oxford book the editions of these texts are mostly taken from editions published by Oxford. While they certainly don't have a monopoly on the best editions of these works, they're generally among the best available.
In general this is a very good collection that ought to contain most or all of what the majority of ethics instructors typically assign in their courses, and at a price which is reasonably competitive.