Action! I could hardly believe how much action was packed into this film; it felt as if it went past in an hour! Yet its viewing time is 3 hours. If you think about it, the book is tiny. Its amazing enough that Jackson decided to release The Hobbit in three parts, but still manages so much action in the first film - for three solid hours!
I watched it in 3D, 48fps. Yes, I agree with the many others who say that it makes it feel as if you were right in the scene. More accurately, right in on the set, with computer layered backdrops surrounding you. I don't know if it is just me, but the lighting or set, or something, made it visually extremely unrealistic the whole way through, from the opening scenes with the candle lighting to the Thorin-Azog duel near the end (the exception being probably the Gollum scenes - and Andy Serkis was amazing, as expected). It wasn't so much the CGI and editing, but more the sets and lighting that achieved this negative effect
Martin Freeman played Bilbo very well; his humorous character was a great reflection of the book's light-hearted storytelling. Of course, on the whole, the film was more serious and darker than the book, but a semi-detatched fairytale style would never work for a movie.
Likewise, all the other characters were brilliant, the dwarves especially. I have read some comments on the differences between the portrayal of Gimli from LOTR compared to the portrayals of these dwarves in The Hobbit, how Gimli seemed more serious and felt to the audience as more competent, confident and knew what he was doing. This, of course, cannot be said for all the 13 in The Hobbit, "Bend the forks and smash the plates, that's what Bilbo Baggins hates!" and all. Do remember that Gimli was from a war clan, and most of these 13 were not, they were miners and blacksmiths, farmers even, perhaps, so do not expect the solid Gimli performance from them.
A note on the portrayal of Erebor. Too grand, too showy, I reckon. And the dragon was disappointing. With movies like Eragon, though nowhere near this standard, the dragons were beautiful creatures. Smaug did not quite manage that terrible beauty aspect that would have made him the highlight he should be.
Music. Absolutely amazing. Howard Shore is an amazing composer, and his themes ring with the essence of Tolkien. The main theme for the film series really brings to mind the grand caverns and massive mountain chambers of Tolkien's dwarven lords "in their halls of stone". The haunting, almost a capella Misty Mountains sung by the dwarven company was exhilarating to listen to, applause to Richard Armitage and the others who had to learn to "sing like dwarves", and made a great job of it.
With the Lord of the Rings trilogy being 10/10, I would rate The Hobbit: An Unexpected Journey 6.5/10. Peter Jackson is an amazing director, Howard Shore an amazing composer, but some kind of apex was reached in LOTR, and I had always known that The Hobbit would not reach that standard of satisfaction for me, with or without new technologies. I cannot say it was bad, however - it wasn't. But neither did it impress much, to be honest.
In any case, I am looking forward to The Desolation of Smaug.