This is a perspective from someone who read the book twice before watching the movie :
HOLLYWOOD RUINED THE BOOK!!!
Yes. The movie was a far cry from the book. Many characters were changed and the storyline was modified, cutting it short enough for average movie-goer. It is so sad to see them striped and raped a good story apart so that they can fit the whole thing into commercialised movie time.
However, from the perspective of a person who has yet to read the book ( my dad, who is too busy to read books) said it was a pretty good movie, with non-stop blow by blow action and a very surprising ending.
Comparing the book and the movie, the book provide much more details and explanation that the movie cannot give. And the book sound more logical than the movie as in the movie, Robert Langdon seemed to already know the truth and there are way too much coincidences. Plus, the movie didn't really leave much space for imagination or thoughts to ponder. The movie, by all means, is a very good thriller with wonderful suspense and a growing momentum by each minute. But in my humble opinion, it leaves much of the details out, making it feel rather empty. However, I didn't know Ewan McGregor played the Camerlengo. And Vittoria Vetra and Commander Olivetti in the movie definitely doesn't fit my imagination from the book. But the cast did a great job overall. Ron Howard did a great job directing the movie. Hans Zimmer did a great job writing the scores. Screenplay suck because I seriously feel like the story was riped apart and raped of its dignity by such abreached movie.
Ratings : 7.5/10. If you like intellectual thriller and sight-seeing, this is the movie for you. If you read the book, expect to be disappointed like me. If you are looking for some kickass action scenes, look elsewhere.