The acting, special effects and basic story were all terrific, and I'd see it again in a heartbeat. However, notwithstanding Cameron's claims on Fox to the contrary, the message is well to the left end of the political spectrum, and quite heavy handed.
I, for one, am tired of seeing humans in general and the institutions of the U.S. in particular (the U.S. Marines in this case) portrayed in such a negative light by the Hollywood leftist elite. Leave your goofy politics out of my movies, please. I prefer to get my moral instruction at church, not at the movies, thank you very much.