I am impressed by this text, with one caveat. At my school it is used as a graduate level textbook and that is probably the appropriate level.
I am an undergrad and I enjoy this book immensely. I'm constantly finding explanations (finally!) for most of the indecipherable ideas embedded in the critical articles I have to use for literature papers. It's giving me the language to interrogate texts and making my reading experiences much more meaningful. This book gives me food for thought for days.
But if it's brain food, it's definitely health food, maybe even crunchy and vegan. There is some truth in the other reviewers' impression that the essays can come out on the pretentious side. This stuff is hard on the modern entertainment-loving brain, unless your brain is entertained by a challenge. I love this book, but I pace myself to about a chapter a month. Since there are 28 chapters, it's going to take me about 2 years to get through it!
The book it is an excellent compendium of complex ideas. The ideas are never cheated of their complexity and their originators are never given short shrift. It can be gotten through in a semester, but only by using selections. Don't be afraid of this book. It's even reasonably priced. But if you try to foist it on undergrads, you might be buying a rebellion.
A better text for a fast and dirty overview could be Peter Barry's "Beginning Theory: An Introduction to Literary and Cultural Theory." ISBN: 0719062683. I was taught this book at another school and it's great if you're looking for conversational, succinct, 12-page chapters on all the major schools, in chronological order. But you won't get a deep understanding from Barry's book, and it will only frustrate those who actually want an understanding they can take away long after they put the book down.