This review is just about a minor difference between the book and the film, but to me, it is amusing and revealing.  First, I would like to tell a short joke:

A meeting among the writers, producers, directors, etc. for a new movie.
One of the producers says, "Sounds great, but we gotta change the name of the movie.  I know what an optimist is, and you all know what an optimist is, but how many of the dumb schmucks out there know it's an eye doctor?"

The funniest part to me, is when you try to do any research on the film, you get the line, "I ate his liver with fava beans and a good Chianti", and the famous Dr. Lecter sucking scene.  That is considered one of the major scenes that defined the good Doctor's character.  But other than his iconic relishing of the memory, there is no particular subtlety in the statement, except for a possible connection between "liver" and "Billy Rubin".

In the book, however, Dr. Lecter actually says, "I ate his liver with fava beans and a good Amarone", quite a different story.  Although Amarone is the fourth most popular wine in Italy (Chianti being the first), I suppose the Producer thought that nobody in the audience would know it's a wine, and would therefore be confused instead of terrified.

Amarone, compared with Chianti, is rich with dangerous implications, symbolic of Dr. Lecter's character.  Amarone is made with the help of the Botrytis fungus, known as "noble rot".  When the grapes are infected with Botrytis in the evening, then dried by the sun each morning, they become sweeter and the wine is made richer.  But if the Botrytis stays too long out of the sun, the grapes rot and are ruined.  Dr. Lecter has the brilliance and nobility on the surface, but whatever helped drive that has stayed too long, and he is now infected with the noble rot.