First of all, forget all the five-star reviews. This is a good book, but it ain't THAT good. I guess since this is the only legit book on the work of Steven Seagal, hardcore fans can't help but go overboard in praising it. Also, the irony of having a talented writer treat Seagal's filmography as a serious "body of work" makes the book seem funnier than it really is. Expect to be amused, not to be ROTFL.
The first thing you need to understand about SEAGALOGY is that it isn't as tongue-in-cheek as you'd expect. Vern is an honest-to-God Steven Seagal fan (yes, those do exist) who takes a sincere interest in every facet of the big guy's career. Whenever he gives Seagal a hard time, it comes across as a good-natured ribbing rather than a genuine put-down. There is much about Seagal to both admire and criticize, and Vern is one of the few people to maintain a fair balance between the two.
The big problem with this book, though, is that the majority of it consists of plot summary. If you are already familiar with Seagal's movies, the constant barrage of story details gets old quickly. If you're trying to figure out which Seagal movies you should watch, this book will spoil the plots for you. The only people to whom I would whole-heartedly recommend this book are those who prefer to read about Seagal's movies rather than watch them. Unfortunately, I'm not sure many such people exist.
Most chapters in SEAGALOGY are little more than dressed-up movie reviews. Vern goes through each film in detail and provides a certain amount of commentary on what works and what doesn't. Most of the humor comes from him pointing out plot holes and various absurdities the average viewer probably missed. It's also great for clarifying the confusing elements found in each movie, which is no small matter because several of Seagal's films have been cut, re-edited, and stitched together worse than Frankenstein's monster.
For me, the best part of the book was at the end, when Vern provides an overview of all the specific traits that make a Seagal movie a Seagal movie. I think he's right when he says that Seagal's movies carry a specific imprint and wouldn't work with a different lead actor. For example, if Dolph Lundgren had starred in FIRE DOWN BELOW, you'd be saying "Why is Dolph behaving like Steven Seagal?" However, if Dolph Lundgren, Jean-Claude Van Damme, and Wesley Snipes all decided to use each other's scripts, it's doubtful anyone would notice.