I have to say, that they did a pretty decent job adapting the book to film. The flashbacks from the book were handled very well, and in a way that didn't lead to overly long and dull exposition. It's very hard for me to not compare the book to the movie in this review, I have watched the film times beyond counting (I'm on my fourth copy: one loaned and lost, a second the tape busted on, and a third scratched). I'd have bought the anniversary edition, but it didn't have enough bonus material on it. It is a favorite movie in my house, in fact, it's one of the movies that I'd bring with me to a deserted island.
Ok, back to the book itself. I was inspired to reread it because of the Twitter Geek Girls Book Club, a book club for girls that aren't into chick-lit or romance novels (at least not only those). Goldman's approach of "abridging" a historical satire to make it enjoyable for his son and recreate the story that his father read to him is endearing. His use of asides adds to a feeling of intimacy with the author, and the characters in a round-about way. The reader can feel his nostalgia emanate from the page, in much the same way that I have a soft place in my heart for the movie. So much of the book was in the movie that it is very hard for me to separate my feelings for the two.
There were several parts of the book that I wish had made it to the film, though I understand why they did not. Inigo (most everyone's favorite character) returns to the Thieves' Quarter after encountering the "Man in Black", a place that he hates. He is wishing that he could wear a sign that says, "Be careful, this is the greatest fencer since the death of the Wizard of Corsica. Do not burgle." That struck me as quite funny, most likely due to the use of the word burgle.
If you are looking for a gently funny book with action and adventure, or if you are simply a fan of the film, I suggest picking this book up. I plan on trying some more of his works. If The Princess Bride isn't your sort of thing, remember he also wrote "Butch Cassidy and the Sundance Kid".