I listened to an audio version of this one (1hr21minutes). If I had been reading it I might have DNFd.
Being a novella, the story itself was short. Some attempt was made for characterization but I didn't feel much for any of the characters. Samantha came over as whiny and annoying, and though personality change was mentioned in Richard, other than being a jerk for a few sentences he was pretty much a non-entity in the tale. Some mention was made about the necklace and it is inferred to be the cause of the conflict in the story but other than Samantha being annoyed by it in the early scenes of Richard coming home we learn nothing about it. The ending wasn't what I had expected but wasn't enough to save the rest of the story for me.
I didn't entirely hate it, but it was just okay.