This show has the blessing of getting Terry O'Quinn as its main villain. It also has the curse of opening in a universe where FX's American Horror Story already exists.
666 Park Avenue refers to a hotel where people who check in tend to make deals with the devil. It centers on two new managers (Rachel Taylor, Dave Annabele) who move and will be learning the secrets of the hotel over the next few weeks. Meanwhile there's an anthology approach, where a tenant of the week goes through the struggle for their soul.
I liked the episode I saw okay, but not enough to follow, and since it's not doing too well in the ratings, I don't see it surviving for a second season.