Just watched the movie. It differs significantly from the book, imo. Tries to be a bit of an action movie, whereas the book paints more of a picture of a guy going to work everyday, and his job just happens to be to look through a scope for hours and hours.
The movie fails to convey many points from the book I thought were really enjoyable, but no movie can ever encompass all the great details that a book can, so I get some of the omissions. Didn't think this was one of Eastwood's better jobs, and it barely even felt like an Eastwood movie, right until the ending tribute section, where Eastwood really shines. That section was extraordinarily well done, imo, and the movie is worth it just for those final minutes.
Was also pleased that it didn't turn into a political thing. It stayed focused on the man himself, the sacrifices he and his family made and the service he gave -- as it should be.
Well worth a watch