I saw this movie a week or so ago. In 2D, on a laptop screen (hey, someone I was visiting had already downloaded it, and it was snowing outside, don't look at me like that), i.e. without the cinema experience plus points. And I still thought it was pretty stunning.
When the CGI first came in, i.e. he first adopts his avatar body, I thought it was kinda awkward, but once they actually go into the forest, it got amazing.
I have to admit, I loved the Apocalypse Now reference. Anyone who has seen Apoc Now and missed it must have been watching this asleep.
The people bitching about unoriginal story are just silly. Yes, it's cowboys vs Indians, but it's been chucked into the future. As in, the historical context which normally limits the possible endings of these films disappears. The Indians can actually come out victorious. Once I realised this, I was so excited for how the end might play out. All Cameron had to do was make it feasible that the Indians actually could win this time, and I think he did so.
My biggest bitch has to do with the end of the fighting. The main character running up and launching himself at the Colonel's spaceship to take him out with a grenade, I loved that. But once it got down to the big one-on-one showdown between him and the Colonel in a robot with his girlfriend pinned underneath a horse, it just felt a little too wank wank "now it's personal" big-action Hollywood ending for the sake of it. It could have ended with the ship going down and him being swamped by Indians and it would have been a satisfying enough finale for me.
Other than that, pretty much brilliant movie. I might go see it again at a cinema in the next few weeks, though I'll have to travel some way to find it in English.