I absolutely loved the book, and I only quite liked the film. Even though it was an independent production, it still felt Hollywood-ized. At times I felt the book was just a tad too sympathetic to the Weather Underground, but there was no such danger with the film. I haven't done a textual comparison between the book and the film's dialogue, but it felt like most of the politics had been squeezed out of it. There wasn't much sympathy for the Weather people at all - all of that was reserved for those who wanted out of it. It was much more of a conventional 'clear my name' and 'fugitive' type film. The FBI agents didn't seem menacing - the close-ups humanized them. The Osbornes didn't have the right-wing populist politics that they had in the book. And the actors were all much too old - Robert Redford looked at least 70, which made the chronology a little nonsensical.
Still pacey and enjoyable, but a missed opportunity.