Slack is GREAT! He’s a happy-go-luck guy, young, and absolutely full of energy, which is a big change from the usually boring teachers. He's always making sure everybody understands the concepts he's teaching, answers any questions you've got, and tries his best to get you to interact. It's obvious he's the kind of teacher that loves what he does and tries to get you to like the material too. His exams are easy as long as you know and understand the major concepts he teaches and that you read the book.