I've seen Avatar in 3D twice. Where you sit in the theater and which theater you choose makes a huge difference on the experience.
PepsiMax theater last night was phenomenal. Surround sound and film resolution were incredible. Compared to my first viewing which focused only on the story, which I feel is good, last night's show was the clear winner because I got the story and all the benefits of sights and sound that made me feel part of the action.