Outstanding effects and the storyline does a great job of keeping you engrossed. My kids didn't squirm at all even though it was 2 1/2 hours.
Yeah, it's very much a utopian lefty film... basically Dances With Wolves in Space. The savage is always noble; The white guys are always the bad evil corporate rapists. Particularly American corporate white guys who are military. It seems that Cameron's take on the whole entire GWoT is the al-Qaida guys are just nature-loving people living in their element and they'd leave us alone if we just quit stealing resources from them.
Still, if you are one of the few people who hasn't seen it in 3D I heartily recommend it.