The book is very, very different than the movie. We never meet Oscar--he's already dead. The Ginsberg son, Aaron is not dead, although he is assumed to be. This changes the timbre of the work. I also found The Bat slightly less terrifying in book form than on the screen. For a while you think he's actually an okay person, but then you're proven wrong.
Another thing I'm not sure about is why is Harry Ginsberg black in the movie, but his race is not discussed at all in the book. I know there are black Jewish people. I'm not so closed-minded as to think you cannot be black and Jewish. However, I find it interesting that they took the one racially nondescript character and made him African American while changing the race of Bradley's final girlfriend from black to Italian. What was going on there? I think that perhaps they really wanted to cast Morgan Freeman and who could blame them? I also think that Hollywood is still very mono-racial relationships oriented, unless you want that to become the whole movie which maybe they didn't. I think that if that's the case, it's a sad commentary on society.
I do not know if I like the book or the movie better. Each has it's own points that I enjoy and points I dislike. I would suggest reading the book and watching the movie. They're two very different experiences. I'd rate the book a 7.5 out of 10. I'm not sure what I rated the movie. I'm not sure if I would rate it higher or lower. I think they're about the same.
The last thing this brings up for me is how some authors allow their work to be manipulated just for money. I'm not saying that I'm above this. If I ever have a book published and someone wants to make it into a movie, I will allow some latitude, but I don't think I will let them change basic character attributes such as eliminating the black doctor in this story. Or making Mr. Ginsberg black which would explain why the interracial marriage was never discussed in the movie. That never made sense to me. If you're going to get married in the 1950s to someone of a different race than you. That's a pretty big deal you would think they would explain. So maybe Charles allowed them to change the girlfriend, but insisted they had some black character somewhere. From what I understand, if you actually tried to marry a person of another race in the 1950s (providing it was legal where you were) you were likely to have visits from the KKK. Based on the article that my assistant just found, they theoretically could have gotten married. The first state to allow this was in 1948, so it's not entirely inaccurate, just mostly. It wasn't legal in the whole country until 1967. But I still like the book. I just have a lower opinion of the movie now.