I saw Beowulf in 3d this weekend and honestly, I don't really feel like it added that much to the experience. Sure, they could spatter blood at the audience and throw weapons at us, but how exactly does that improve my viewing experience?
I did not, for the most part, enjoy the digital imaging animation technique. The opening scene, in particular, was very disappointing - people looked stiff and unreal. Also, no one's eyes seemed to either be alive or tracking properly. The only thing I liked about it was the truly aged look they managed to get with the characters that survived from the first to second half of the movie. Sure, most of the time they didn't look as creepy as the people did in Polar Express - but that's not saying much, because Polar Express was _really_ creepy!
3d gives me a headache. I guess it's because of the eye strength thing, plus the glasses were pinching against my head, or pinching my prescription glasses against my head. I would rather have seen it in 2d.
Otherwise, overall the story was definately different from the source material, but had much greater depth of character than the original poem (that's not really saying much, alas). Grendel was interesting and definately horrifying. The dragon was awesome.
/ali