I have long been a fan of Nora Roberts, but never had the chance to see any of her work retold in a movie. It was definitely worth the wait.
I don't think the plot was altered all that much from how the story was originally told, although there were some things added or changed a bit to throw suspicion around.
The parts that were cut from the story(understandably) did not detract from the movie version - both were excellent.
I could identify with both of the lead actors as playing their characters straight from the book. Johnathon Schaech was especially good as Brody and was well matched with Heather Locklear as Reese. The other characters fit in almost as well, with some minor differences that I had pictured in my mind. But, of course, everyone sees things a bit differently.
I hope the next three movies are done as well as this one was.