I have not seen the film but have read extensively online what all the critics are saying about it. The "negative" reviews usually fault the film for being too slavish to the source material - as in the reviews mentioned by Lapis Exilis. This was my "fear" as well when I heard Snyder was given the project.
My gut feeling is that, over time, the film's slavishness will become less important and people will
accept the film. I think history will be kind to the film.