Why do you have low expecations for the films? Are you an HP purist or do you not like the score, acting, cinematography...etc?
Because if I don't have low expectations, I end up getting upset. I'm disappointed when they leave out or change things that I was looking forward to seeing. I understand that they can't keep everything because of time constraints, I just have issues with some of the things they choose to keep over others. You know, if you're going to cut the majority of Voldemort's backstory, don't add a long, useless chase scene in a cornfield that results in burning down The Burrow and does not advance the plot at all. Don't waste time with a Durmstrang/Beauxbatons dance sequence for no reason if you don't have enough time to make the maze as complex as it was in the books.