OThe first thing I will say is they better make parts 2&3. Full review to follow, but I loved it and that most of the things people were complaining about were what I liked best about the film.
A need to know much of the backstory, limits the appeal to those who haven't read the book. A five minute briefing on themes, good guys v. bad, etc would make it much more enjoyable for them.
The film was beautiful to watch, slowly paced and lingered on the characters like they were iconic statuary. Which, in a way, they were. That was great way to allow thoughts and alliances to form. Bottom line, I loved it.