One thing I think the film got heinously wrong was actually Fanny's uncle, Sir Thomas. He was made out to be an entirely unsympathetic character really, when in reality he is merely a bit stern and scary to a timid young child. The sending away of Fanny to Portsmouth apparently as a punishment for refusing to marry Crawford was very much not the case, even if he hoped she might see things a little more clearly as a result of it. And the thing with the slave trade really really got on my nerves too. It also seemed exceedingly sad to me that Fanny's faithful brother William was entirely written out, even if Susan got a larger role than she might have had otherwise.
On the whole it all seemed very much the worse for being hurried through. We miss most of the things which make Fanny who she is, and make her so certain that Crawford is not someone she could love. Her briefly accepting Crawford's marriage proposals is entirely an invention which grated on me, as no obvious reason was given for her changing her mind again so suddenly, which is very out of character. Bits of dialogue from the book are scattered about the place, seemingly at random. Usually from the right mouths, but in entirely the wrong places. The scene towards the end with Mary Crawford speaking out in front of the entire family was originally a private conversation between her and Edmund, and made very much more sense in that context. The whole theme of good principles and the lack of them and the difference education and situation can make is entirely lost it seems.
I don't know if it would be a bad film, to someone not familiar with the book. I certainly thought it moderately well acted in places. I was glad to read the book again though. Fanny is not the most lively of characters but it's still a sweet story. I never seem to tire of re-reading Austen, and though this is not what I'd consider one of her best it's much more than the film could ever be.