I have used this set to help organize sermons, and so far, it has been very valuable with the outlines and expositional commentary. Commentary is concise, so other resources are necessary. However, it has been good as a beginning point for an understanding of the big idea and context of any text.
You may already know that the Warren Wiersbe commentaries are a very good balance of conservative Bible application and scholarly highlights. So then the question is which of the three publishing versions to buy. I have purchased all three. I say this 6 volume set is the best deal for the money and printing quality. This 6 volume set has the thickest, best paper, it also has larger text than the two volume set, (but the dozens of paperbacks version have the only advantage of having the largest text size). I love this six volume set. It is the most durable printing quality of the three ways that this publisher sells the Warren Wiersbe commentaries.