A good companion to the superior book....
The film isn't a total failure--It's beautifully shot, well acted, and has a gorgeous score. But I feel like the aspects of the book that were downplayed/changed kind of wrecked the potential of the film.
The reason Diana's death is so shocking in the book is because of the plot layout. We spend the book assuming Maureen was killed because we hear Diana say it in the beginning: "Kill her, not me." We then revisit it in the end of the book,and learn that Diana is shot after giving up her friend (Maureen 'volunteers' to be the one killed.)
I think the filmmakers felt Diana needed some kind of redemptive arc, and maybe it's a bit too mean to have her killed after giving up Maureen to the killer. Better to have her have a last minute change of heart and give herself up instead. The truth is, the story would've been tragic no matter who was killed, but it stings since Diana had so much life to give.
Also, the book had an almost supernatural element that I'd have liked seen in the film version. There are ghostly animals and logical hiccups in Adult Diana's life that make you think she's just losing her mind. I'd have like to see Thurman be able to go this route with the character, instead of one simply wracked with guilt. I feel like she got a bit cheated with the screenplay's version of older Diana. I'd like to have seen her go bigger with the character, but most of the events they put her though didn't seem to mean much. (The Emma/spaghetti scene in the book is really unsettling, but in the film, doesn't seem to signify anything).
I just feel like with a little more time, care, and attention to the book, this could've been a knockout. Maybe the book would've been to hard to adapt literally, but the film is a bit too muddled. But still, gorgeous, gorgeous, gorgeous.