I saw this in 3D, but it really was not a key factor. The story doesn't change without it. It pulled the heartstrings and thoroughly enjoyed it, but I still think the first 2 are the best.
After hearing and reading negative reviews, I went in with lower expectations. I have not read the graphic novel, but my friend had and both paid top dollar to see on the Cinerama screen. First I agree the Rorschach is the best character in the film. Dr Manhattan is fun, so is Nightowl and The Comedian in the back-story.
Since I did not read it in advance, I had no expectation, but I enjoyed the plot and the action. I was never bored. From what I gather, it is mostly following the graphic novel, but the ending has changed. It still has to stand as a film and a very good one. It does. This is not for everyone’s taste, but those who like science fiction, graphic novels, lots of action and an interesting plot, this one is for you.