Instruct: Classify a given Amazon review as either positive or negative.
Query: Great resource!

I purchased the audio book, which I was able to get through in about a week during my lengthy commute to work each day. After listening to it though, I ended up buying the hardback book as well. I needed something in writing that I could refer back to. So, I would recommend just purchasing the hardback so you don't end up spending double, like I did.