I'm also part way through my first reading of the book and I'm enjoying it...every gritty detail, every over indulgent character development, every nuance that becomes an integral part of the movie. But I do find myself constantly comparing it to the movie. It's hard not to picture the cast as we know them while reading the book. And even projecting the cast into the parts of the book that never made it into production.
I believe my point of view will always be clouded by the fact that I saw the movie before reading the book. And in some ways, I find myself wishing I had read the book first.
I think there are things in the book that could have been incorporated into the movie but couldn't be achieved through dialog. Puzo is heavy on narrative which contributes to the progress of the novel, but wouldn't translate well on the screen. Moreover, how much longer could you make the run time for each of the two movies? I guess if Robert Evans really had his way, they would have checked-in at around five hours!
Turnbull's frequent references to the book motivated me to visit my local public library for a copy. I think you have a greater appreciation for the casting and the screenplay while becoming much more critical of the movies once you read the book. But I would guess virtually all of us have seen the movie first and our opinions will always be just a little bit biased because of that.
tony b.