The story is interesting. It gets significantly more interesting, however, in the years after Charles & Diana's marriage. Granted, this book was written prior to the fascinating years therein, but, in comparison, it grew dull. I personally disliked the writing as well, leading to a fairly unenjoyable reading experience.
This book was kind of craptastic. A beach read when it was relevant, I bet this author felt really dumb in the mid nineties. I was amused by it in retrospect.