This book is one of the better studies I have read.  I was hesitant to buy it because I did not have as good of an experience with the Smart Guide Book of Hebrews.  The book of John takes you verse by verse adding excellent commentary all along the way.  The authors explain a lot of confusing verses by informing you of the culture back then, Roman laws, Jewish Laws, and traditions.  These explanations paint an excellent picture that supplements the Biblical text in a very informative way.  This book also added a lot of value and discussion to our small group study.  In summary, the Book of John by Smart Guide is a great read for either someone who wants to learn in depth the Book of John, or even as part of a small group study.  I highly recommend this book.