First, a disclaimer: I saw this on an Ultra Screen, which is a big screen, but was not in 3-D. I don't know that seeing it in 3-D would change my opinion of the movie a whole lot, although maybe I would be wowed by that gimmick.
If you have seen Independence Day, Dances With Wolves, Return of the Jedi, and Brigadoon you have seen this movie already--save your money. If you haven't seen all of the above, use your money to rent them and skip this movie. If this is the future of movies, the future is bleak indded.