Dr. Sproul is a well-known and respected author. Some of his works include The Holiness of God, Chosen by God, and Now, That's a Good Question!. Sproul is also the head of Ligoneer Ministries and Pastor of St. Andrew's Chapel. To many, including this reviewer, Sproul has been influential towards understanding Biblical Christianity.
However, the commentary on John is not his best work. While there were some good nuggets found in various chapters, the commentary lacked Sproul's engaging style, did not always completely cover the entire topic and the writing style seemed abrupt at times.
For instance, in the chapters on the "Woman at the Well", he never covers the last part of this section in Scripture and the end of Chapter 10 seems to abruptly and awkwardly end. Whether this is a result of poor writing on Sproul's part (which I doubt), the editor's poor editing, or his messages were poorly transcribed from his teachings at St. Andrew's Chapel, I do not know. The commentary is not "in-depth" and many of the practical applications will be familiar with those who have studied Sproul for many years.
There are some positives aspects of this commentary. Sproul tells good stories. Whether he is talking about a man with an IQ of over 180 (Chapter 11) or when Sproul caught a thief (Chapter 12), those who love listening to him can almost hear his voice as he is telling these stories. As well, this commentary is faithful to historic Christianity and is easy to read for everyone.
If you are new to Sproul, I would highly recommend any of the above books mentioned in this review. Sproul is a great author who has produced a myriad of great works and has written many books that will excite your soul.
While Sproul will go down in history as one of the greatest communicators of reformed theology of this generation, I doubt his commentary on John will be used as evidence. While I respect Sproul greatly, I would recommend another commentary on the Gospel of John.