Let me begin by saying I read this book from cover to cover. I'll also mention that I'm a grad student in neuroscience. This book contained a few moderately interesting insights, but overall covered astonishingly little information. It's so full of the author's anecdotes about who he met and how he came to his conclusions that it leaves little room for his actual theses. It's a lot of flash and little substance. It's definitely well-written though.
There are so many incredible things to learn about neuroscience that are accessible to non-scientists, yet he focused most of the book on electroencephalograms (EEG), which is ancient technology and alone yields little information about the brain. He drew broad conclusions from specific data and consistently overinterpreted results. This is not surprising considering he has no degree. I should have noticed this before I bought the book. He's like the Ken Burns of neuroscience. You can't study neuroscience part-time for a year or two and expect to write a deep book on it. It's like trying to fly a space shuttle after a summer internship at NASA.
So in conclusion, if you know nothing about neuroscience, you'll probably get something out of this book. Don't waste your time on it though, because if you want to have your mind blown, read "The Man Who Mistook His Wife For a Hat".