The good: This movie is beautiful. The acting was pretty good, too, even if some of the dialogue was kind of cheesy.
The bad: After all that work on appearance, the plot was phoned in. There are no surprises here. None. Every one of Chekhov's guns goes off exactly the way you'd predict.
Other people have commented on the implicit racism of having the white guy come to be the leader of the differently-colored natives and on the two-dimensional (at best) military/industrial villainy; I attribute both of these more to laziness on Cameron's part.
That said, it was still worth the money, and I'd recommend it. Just don't expect to be surprised.