I really went into AVATAR expecting to hate it, and was pleasantly surprised, as I have been a number of time this year with popular movies. You see, it pays to be a pessimist. You're constantly pleasantly surprised. It must really suck to be an optimist, you're constantly let down.
Anyway, even though the film was way too long, mostly in the first half, the story was very, very trite, and the main character was weak, I was still entertained. Most of the acting - other than the through-character - was actually quite good. But that's a pretty big weakness when the main character is bland, and it's tied tied to bad writing. (Good god, the voice-over was TERRIBLE. It was interesting watching THE INFORMANT in the same day, where the VO was brilliant.)
The visual effects were pretty brilliant. The sound design was amazing, and the music was pretty good too. From a technical standpoint it was probably the best film of the year.
We saw it in Imax3D at an AMC theater. Imax does not advertise which of the 3D technologies is on which screen. Unfortunately this theater uses the Real3D technology, which is the polarized lens system. The Dolby3D system is vastly superior. The glasses are electronic and use a shutter system to keep the two eyes in sync with the two projectors for a crisper image. The Real3D polarized lenses by definition allow half as much light through each lens, so the image is definitely darker. This was a big problem with this film, where much of it is in nighttime, and the characters have dark blue skin and all end up looking alike.
I am not at all a fan of 3D to begin with. I have poor vision, especially at night, and have always gotten headaches with the glasses. This was no exception. In fact, my headache started during the trailers for other movies and was in full force by the start of the feature.
I think 3D is a gimmicky fad which will pass again. It did not in any way add to the movie, and in fact detracted from it in many ways for me. It never looks like there is actual depth, instead to me it looks like a diorama, where there are a couple of planes of flat images, and not true depth. It's not like we're looking at a hologram. We're still looking at a two-dimensional image. The only places in the film where I noticed 3D were a distraction. There were quite a number of scenes where planes appeared blurred, or there appeared to be no depth at all.
I would probably not sit through the film again, but if I did, I would make sure it was in Dolby 3D. I'm not sure the Imax screen added anything. It was not shot in Imax, the only benefit was the size of the image.