Read this, if for no other reason to understand, in a fun way, those sweet, early, open, pre-commercialized days of the Internet in the 1980s and 1990s. Don't knock it: nostalgia is a great motivator.
Full disclosure: I found 2600 magazine in high school (among the zines at a local indie record store, fortunately) and had several Free Kevin stickers. The downright illegal means used by law enforcement to pursue Mitnick, and the legal system's irrationality and unjust punishment of him, provided one of my earliest and most memorable lessons about corporate and government collusion and power, and I wanted a refresher course as well as more information than I had in the early 1990s. Hence, this book.
Mitnick does a terrific job describing technical concepts involved in hacking, that I think are easy enough for the lay person to understand, especially because most of his tactics involved social engineering: calling people up and asking for information outright. This is key, since most people's concepts of hacking is focused entirely online. I remember when I worked in technical support, for example, and ran into some fraud cases. For credit cards, it was easy to predict (down to the exact 2-3 days each month) when fraudulent purchases would spike, because we knew their statement cycles and thus when paper statements would arrive in mailboxes. (In the late 1990s, they still bore the full credit card number.) Almost all online purchase fraud at the time was due to simple mail theft.
Mitnick does not try to make what he did seem overly complicated or focus on the technical aspects of hacking to the exclusion of the social ones: he doesn't try to get the lay reader to admire him even more by belaboring these points, as he could have.
The book is just packed with great anecdotes and highly entertaining. As others have said, it very much reads like a suspense novel at times. Mitnick's honesty is refreshing, as it's there even when it doesn't cast him in a "glorified hacker" light: Mitnick is honest, for example, about the extent to which he depended on the kindness of others, and how he lived when he had little or no money. Hackers tend to be represented by the media as if they spend their days flying between Monaco and the Cayman Islands (and I'm sure some of them do), but it's a myth that Mitnick does a nice job of busting with detail about his life. It's strip malls, Kinko's and Sizzler rather than Corsica and Durban.
Mitnick has always maintained his innocence, so I expected a lot of "I did not do this," but that's not what you get. He very much describes what he did, but is also very clear about what he did not do.
The book is very much a public service because it provides specific, well documented detail on the lengths to which law enforcement officials will go to frame someone, essentially, and put them in jail simply because they want, "feel" or "believe" they belong there, even when there is no evidence. There was, in the Mitnick case, tremendous lack of responsibility and professionalism on the part of the FBI and several police departments, and the public should know the specifics. The FBI needing to, and illegally hiring a civilian to, catch Mitnick, for instance, indicates that he most likely would not have been caught by law enforcement alone. While this does, yes, cast Mitnick in a more sympathetic light, it's much more valuable than that.
Finally, it was simply nice to hear Kevin's voice. It's a nice balance between personal, memoir style content and technical stories. It definitely makes me want to attend one of his talks.