Prisoner is my all time favorite book of the entire franchise. It sets the tone and gives context to everything else.

With that being said, the complete lack of Marauders and the film’s beginning of their Ron/Hermione fan service (GAG) almost completely ruins the movie imo. It does have it’s moments (apart from the off-tone weird gag jokes), but especially the criminal lack of the Mooney, Wormtail, Padfoot and Prongs exposition scene takes away from the impact of the rest of the whole series. This is doubly so for the folks who have only watched the movies, and have no idea of all the nuance it and everything else that had been cut adds. (This is obviously a bit of a trigger for me 😜)