It really helps to already be familiar with some of the ideas in this book. I had previously read Kahneman's, "Thinking, Fast and Slow" and I highly recommend reading this beforehand or after if you still have some questions.
The book touches on many of the ideas from "Thinking, Fast and Slow" but not in so much detail and not with the progressions that TFS does. To those that felt like the first 200 pages didn't get at the core issues, you are somewhat right, so I encourage you to read TFS. However, I don't see that as a reason to not finish the book.
To those that thought it was a waste of time, I am tempted to think you are like the same experts who dismissed the ideas in this book or like the experts that thought/think we are rational by nature and rationality is defined by how we act (kind of like the philosophical theory of "meaning as use"). Anyway, if that's the case, I think you should read this again and more carefully next time.