Let me get this out of the way first.
James Cameron needs to hire a script doctor. Not for plotting (although it would help) but for dialogue.
It is really not his strong point at all. Calling the life force of the planet the "Tree of Souls" is so 'Ferngully'.
Do not translate the Na'vi language - it is seriously distracting.
That being said I was completely blown away. The story may have been weak, but the momentum never wavered.
I was never bored.
Absorbing this new world was humbling. So much thought went into it that you cannot help but be awed. From the plants, animal life and landscapes, it all felt organic. The highest compliment I could give is believed in this world and am very sorry it does not exist.
The other think that blew me away was the character animation. I was doubtful at first, but the Na'vi blew me away with their authenticity. Zoe Saldana impressed me to no end as the warrior princess. I honestly believe that a motion capture performance should be considered in the major awards acting categories. When they are good you can tell. People may argue that a performance is enhanced, but what is the difference between that and a CGI tear added to Jennifer Connelly in 'Blood Diamond'? None in my book.
Saldana's Neytiri is up there with Andy Serkis as Gollum and King Kong. A true performance, captured. The passion displayed in her is astonishing.
She even makes the dialogue work for her.
This was my first movie in 3D and I have to say I am a convert.
What Cameron managed to do is pure cinematic magic.
Grade - A-