In the class we creating production paintings - which are basically very detailed environment designs. We started with thumbnails, and worked our way to finished illustrations. His critiques are very solid and full of information. He will explain exactly why he is doing this and why it's making the concept more interesting and/or read better.
The only thing is that the class is not for beginners. The concepts he teaches are pretty advanced in my opinion. So I would recommend having a pretty good foundation before taking it. Otherwise - it's pretty solid class and you will learn a lot.