This book is a true masterpiece, which shows Empson's commitment to Literature and, more than anything, his sense of detail and criticism. It is heavy-going, it is rather difficult to read, but as with anything, if you read the difficult parts a couple of times, you will get a true sense of the meaning.
I bought this for an essay prize, the title of which was concerned about how literary writers use ambiguity (or why they don't?). It was very helpful for this.
Thoroughly recommended for the undergraduate or the high-calibre A-Level student.