My husband and myself both really enjoyed this movie. I thought the acting by Jennifer Jason Leigh was quite good and also by Ben Chaplin. But I felt Albert Finney was superb! I also very much enjoyed the book. Yes, they may have exaggerated her character to some degree, but being a person who suffers from social anxiety, and who also went through a supremely shy period in my adolescence, I can relate. They may have made her more inept in the movie, but I feel it didn't ruin the movie, as I just viewed it as her being someone who grew up in a household devoid of real love or any proper guidance for her lot in life. Plus the fact that she felt inferior because of that lack of love, and her fathers seething and insidious resentment and disappointment in her.
I normally, as I do now, rate a movie on it's superb and subtle acting and it's ability to be thought provoking and moving, which this movie had to some degree, but I did also enjoy the beauty of the film that was brought about by the direction and set design of Agnieszka Holland.
No, I would not put it on my top rated movies for acting ability, though, as I already stated there was some solid acting, and Albert Finney was a wonderfully awful father, with nice subtlety, and I really enjoyed the acting of the woman who played Albert Finney's sister - though I cannot remember her name.
All in all, for a modern American movie I feel it was about as top quality as you're going to get any more. There was a bit of caricaturistic acting by Maggie Smith and some light acting by others, but still somehow it was intriguing and enjoyable. I felt it was compelling and very interesting, and very poignant. I also feel the subject matter of the plainness (or less pejoratively - averageness) of a woman's appearance affecting her value as a desirable human, or wife is quite a sad commentary on societies mores and values.
That being said, I loved the movie! And I felt deeply for Catherine's unloved, devalued and tread upon character. I felt the ending had so many captivating emotions and reflections to chew upon.
I would definitely recommend this movie to those who don't depend upon the special effects and magical thinking of Hollywood to entertain them, but like good acting and good old fashioned stories, that absorb your thinking and emotional processes.