John MacArthur is a great preacher and teacher of the Word; however, I was immensely disappointed in this commentary. As a devotional commentary, it would be very helpful as an introduction to James. The problem is that it doesn't so much comment on the text as James, as much as it uses James as a launch pad to discuss topics brought up by James, often only tangentially related to James. The comments are primarily some definitions of the Greek words, but even these definitions are often tendentious. There is some exegesis (usually), but this is followed by a pastiche of verses that ostensibly explicate or expand on the topic. These catenas of Scripture passages keep MacArthur from focusing on the text and the message of James, preferring rather to discuss what Paul or John or a Puritan preacher said about the same or a related topic. James is a powerful book. His message deserves to be heard on its own.
If you are a pastor, I implore you, please do not make this your study tool of choice. Recommend it to your people for their reading, but feed yourself with meatier works.