Well, I went to see The Desolation of Smaug with a seminarian and a nice, single, young man who knows his Tolkien.
Positive and negatives:
Positives first-the pace is fast and one does not realize how long the movie is because of all the action. We missed the first 15 minutes owing to ice, but I can make that up later. The pace is ok by me.
Second positive, the characterizations of the dwarves are more serious and less comic, and therefore, in my humble opinion, more believable. Thorin II Oakenshield, as a character, seems more complex and well-portrayed. He is obviously a complicated "person", and as those who know the book, he becomes more complicated before the end of the story.
Third positive, some of the humor of the original book is in the movie, and some has been added. More on this point below. One funny bit is the Elven insult about a young dwarf portrait drawing, which is being taken away from Gimli's dad. Well, Middle-Earth is very, very small.
Fourth positive, the cinematography is great.
Fifth positive, the entire way the story is presented reminds me of the world in which we live, which is no mistake, but planned, I am sure. Those men in power in the town of Esgaroth are incompetent, proud, stupid, and just out of touch with reality-does that sound familiar?
Sixth positive, I like the way Beorn is depicted. I am partial to shape-changers in literature, as this creature is as old as Anglo-Saxon literature.
Negatives--many, sadly and the first is that the charm and humor of the book is almost entirely missing. This is a fault of the director, who wants an action film over a tale by Tolkien. I do not mind the pace, but I do mind the lack of humor and the lighter touch of Tolkien, which could be called-hope.
Second negative-there is WAY too much time on Smaug and not enough on Bilbo. Bilbo is the hero of the original book not the dragon. Too much dragon...
Third, the interspersing of elements from other Tolkien tales to give background seems unnecessary and over-done. Skip the background of evil and stay with the text, please....
Fourth, the stupid introduction of a red-haired warrior Elf-woman is just plan irritating. Can't we have a story without references to romantic love, female Amazon-like creatures and sentimental love scenes?
Fifth, the entire story is too dark and gloomy. I mean, this is supposed to be an adventure, not a story about the growth of Sauron, which it has become. Too many dark and terrible scenes, which the lighter scenes do not balance out. There are too many dark, decaying, scary cities in ruins. Boring...too many ugly orcs....and too many spiders....
Sixth, and I shall end here, the Elven king in Mirkwood seems way too sinister, even though he is not a nice character at first in the book. He is too cruel, too harsh, and not at all sympathetic.
Well, I hope this is not a spoiler, but merely my own opinion.
Go see it, however, as Martin Freeman is brilliant as Bilbo, and the story does move.