This familiar story did bring the experience down somewhat, although it may have been a calculated risk on Cameron's part. The familiar story allows the audience to accept the alien world more readily. Then again, that could be an oversimplification and this is just the extent of Cameron's storytelling ability. Looking back over his filmography and something becomes clear, more than his ability to rake in money. It becomes clear that Cameron is much better at world creation than he is at storytelling. It is a good thing that he is so good at said world creation, because it helps when it comes time to overlook a film's shortcomings.
Avatar does have a story to tell. It is interesting if emotionally uninvolving. Then there is the environment in which the story is told and the filmmaking skills used to create this environment. In this regard, the movie absolutely excels and succeeds at taking everything to the next level.
When it comes to the world of Avatar James Cameron has unleashed the full strength of his creativity. It is a film filled with with things to look at, from the Na'Vi to the bio-luminescent fauna, dragon-like flying creatures, and the fascinating way the Na'Vi interact with their environment. The world takes new age beliefs to the next level and it works.
I was fully enveloped in this world and would have gladly spent hours more exploring it. More amazing still are the finely crafted visuals that make you forget you are looking at pixels. Add to that the 3D effect and you have one of the finest technical films yet to be made.
Avatar took more than a decade for Cameron to realize on the big screen. All manner of new techniques and technologies were created for his use in bringing Pandora and its secrets to the big screen. I would not go so far as to call this the be all/end all of special effects films, but it does open new doors in the way the various effects can be integrated.
James Cameron has created a technical marvel. You will spend a lot of time exploring the screen, wondering how everything works, how the eco-system works, and how humanity is actively working at destroying it. The 3D opens up the landscape and you will be trying to look around corners and into the deep expanse of the forest. I guess it helps to have that familiar story, it frees you to look around and have this wonder creep around inside your mind.