Funnily enough...I have just finished watching this movie, and personally I really enjoyed it (guess it depends on your tastes) Why buy a movie if you arent the least bit interested in sword wielding action - just to see what the 3d is like? And then bag it when you don't enjoy the movie....
Contrary to all the negative comments on here I actually found the 3d to be pretty good with plenty of depth, how-ever with that came a certain feeling of the 3d being "un-natural" and in some cases almost "forced" There are a few areas where the 3d also looks "rushed" but overall it's not bad.....
Sam Worthington for some reason reminded me of early Mel Gibson (mad max era)...sure the whole thing is rather predictable - but then what movies arent!
Summary - I would say that the movie was "over-slammed" by critics who as usual were comparing the 3d to Avatar! And possibly because it wasnt a box-office smash!
The story flows (and doesn't drag on, and on - my knock at Avatar

), unlike some much better touted movies out there, actors seem to fit their roles pretty well.....if there is one gripe I do have it's that the djin (desert people) seem too plastic looking....It's the kind of movie you really need to judge on your own merits.
Hope this er kinda helps,
Chris