DA
I couldn't agree more. The Johnny Fontaine story in the book, along with the Lucy Mancini story, were completely unnecessary. FFC did the right thing by omitting both from the film.

Having said that, I really enjoyed the rest of the book. I liked how characters such as Luca Brasi, Kay Adams, Carlo, and Al Neri were developed more. The book fleshed out Santino & Fredo much more, which books usually do. I was pleasantly surprised (having seen the movie first) of the subtle differences from book to movie: 1) Tom's explanation to Kay at the end 2) what Mama believed about Michael 3) how Michael was brought back from Sicily 4) and how Fredo was disfavorably viewed by his father because of his actions in Vegas.