Basically this is a manuscript of sorts that an exceptionally bright person had with himself on the issue of quality. On a philosophical level, its rather trite in many ways, as it is just a rehashing of the classic dichotomy between the value of rigorous, analytic inquiry, and the insight that comes from more romantic and impressionistic thought processes. Plato and Aristotle clearly favored the former over the latter. Pirsig takes issue with this and finds them either mutual constitutive or at least in a state of opposition with their own claims to rectitude. The remainder of the work is a somewhat banal novel describing the sights and sounds of travel.
I would only recommend this text to someone who is very much interested in modern interpretations of Eastern Philosophy, as it is somewhat canonical. It also would likely prove interesting to youth who are looking to dabble in philosophical issues without diving into a survey text.
I read this book several times over the years and each time I get something new out of it. I'm a Christian and though this book derives some of its underpinnings from Eastern philosopy, the book gives a great overview of Western civilization. How the book uses geography, the personal relationships, his past history, and Greek and Eastern philosophy to prove his thesis is fascinating. The book has problems. The main character does not follow his own philosophy in some ways. Pirsig makes too broad of generalizations about the Greek philosophers. Phaedrus's experience at the University of Chicago does not ring true to me. However, the book challenges the reader to think, to ponder life in general and contemplate on how the branches on knowledge ties together.
Pirsig's shows parallels between quality and arete (excellence in Greek) and the Buddha. I think there also parallels between Biblical Wisdom and Quality (See Proverbs 8). The book had a tremendous impact when it first came out and influenced a generation of college students. It should be read just so the reader can understand the book impact on current culture for good or ill. Pirsig is a very good writer.