Perhaps the book's most significant insight is that antinomianism refers to more than a simple denial that the moral law has any place in the life of a New Testament believer. Consequently, he is able to demonstrate how antinomianism permeates many aspects of contemporary theology. It offers well-researched and convincing arguments to the cheap soundbites of many of today's hipster Calvinists.
My advice: buy it, read it, and re-read it. I only finished reading my copy on 30 September and already I am considering reading it again.
BTW, his book A Christian's Pocket Guide to Jesus Christ is outstanding, and he has a new book, published by Banner of Truth, entitled Knowing Christ.