I hadn't read a King book in over 20 years, but 11/22/63 made it worth the long wait. For likely King, too, since he first started writing this book in 1972 but stopped because Kennedy's assasination had devastated the author. Plus, he wanted to do much research before writing this book. I'm glad that he waited to finish the story until last year, because the amount of information around the assasination that has developed since then made this book a richer experience for me as a reader.
The book presents the classic question about whether if someone had the chance to go back and to change history would she? The more specific question resolves around stopping the assasination of John F. Kennedy. However, King just doesn't focus on this aspect of the story. There are many layers to the story and many questions about time travel and history that King tackles head on and in a contemplative way. I very much appreciated the thoughtfulness that King brought to the subject matter, identifying many details that one might lose track of when traveling back to the 1960s. The plot is also well-thought out and crafted, which made the story not only plausible, but also exciting to the reader as King answers the "what if?" question.
The ending was satisfying to me but I didn't feel that King knocked it out of the park like he had the rest of the book. In my reading the Notes, we find out that King changed the ending based upon input from his son, Joe Hill. I like reading Joe Hill, but now I am curious to know what King's ending would have been.
Overall, I highly recommend this book. It's neither standard science fiction nor standard King, at least not the King that I knew 20+ years ago.