I thought the book was a bit of a waste of time. Basically, there's tons of exposition describing results that can be summed up in a 2-page chart. There are a lot of quotes from students, but I don't put a lot of stock in anecdotal evidence.
As for students being dissatisfied, I think it's all relative. I'm guessing that grad school isn't nearly as much fun as undergrad, but way more fun than a "real" job.