Hard movie to describe. What's really done well is the story-telling. In a Peter Jackson-esce story-telling manner, the viewer is drawn into the emotional stories and inter-personal relationships more than in previous movies - appropriate, as the characters are growing up and are dealing with "true teenage issues" like infatuation, anger, resentment, fear, jealousy and rage. I also appreciated the subtlety of all the magic - not being all the glitz and glam as before makes the magic appear very believable.
I just hate the cliff-hanger and all the things left out of the movies. I need a 4 hour extended edition that explains everything better.