I've seen it twice now so I'll give my thoughts...
I went in expecting 'Peter Jacksons Vaguely Hobbit-based Fight Movie with Dwarves' and was pleasantly surprised. There were plenty of page-to-screen scenes that I liked and the cinematography was generally wondrous to behold. The CGI was most noticeable in Goblin Town, I think, and it would have been better with models and prosthetics, I think, rather than the over-reliance on graphics. But that may just be my personal preference for models and puppetry.
The padding was more noticeable on second viewing. A few scenes do go on a bit and as beautiful as they were, the panoramic adverts for New Zealand's scenery could have been cut down considerably.
Now, I really disliked the Azog sub-plot. It annoyed me an awful lot and felt shoe-horned in. In fact, I'm pretty sure you could effectively remove it and make no difference to the movie - I'm almost convinced that it wouldn't have been there had this been a 2-film deal and this first outing could have gone as far as the Barrels at least!
I thought the fork-for-a-hand and general fake look of Azog himself was not to my liking. As ridiculous as 'Gothmog' looked in the Return of the King movie, I think I preferred that look to this CGI silliness.
There was stuff I did like. I really enjoyed Radagast. He's always had a special place in my heart as the not-quite-a-failure and not-quite-a-success wizard. He was played pretty much as I imagined him. Also, I am a massive Doctor Who fan, so to see Sylvester McCoy (7th Doctor, my personal favourite) play him was a treat. Though I did fear he'd face the same criticism as his Doctor did. When he first started in Doctor Who he played the Doctor as a clownish buffoon and was lampooned for it. As he went on he toned it down and turned the Doctor into a powerful, manipulative and yet lovable character you could believe was a Lord of Time. That beneath the silly surface slept this immense power and intelligence that he was waiting to unveil. My hope is that in movies 2 and 3 he does the same; we did get a sense of that in this film.
I liked the scene with the hedgehog for that reason. He demonstrates that he is a powerful wizard with great potential, he simply chooses to channel it into a poor defenceless hedgehog. He also holds his own against the Witch King.
The Bunny Sleigh was perhaps a little too much, though. It seems like something that's there to entertain the slightly younger audience - if the burping and falling over Dwarves wasn't good enough. Also, it's probably there for the sake of action figures, let's face it. It was okay in the forest, but the chase with the wargs was over doing it, I felt.
A much more cheerful Elrond this time, too. I liked that. The whole White Council was a good scene for nerds. I don't know how none-nerds will receive it, though. One of my brothers who saw it with me thought they still played Saruman as too "obviously sinister". I didn't get that impression - he struck me as dismissive and unconcerned, but not sinister. I'm glad they kept his contempt for Radagast in, though. I was waiting for a 'bird tamer' line, but alas, was not to be.
The scene where the Dwarves are eating in Rivendel was a missed opportunity, I felt. The music the elves were playing could so easily have been coupled with a few lines of 'Tra-la-la-lally'. They could have made it clear the elves were trying to annoy the Dwarves (which is the impression I got in the book), and given the one Dwarf who stuffs his ear-trumpet, it would have been a hilarious scene!
Goblin Town, as I've said, needed to be toned down. The Goblins in general were a bit too obviously computer generated. There was much more of a 'real' feel to the orcs of the LotR films. Also, the chase scene was really just Peter Jackson taking liberties, I think. It's nothing I wasn't expecting from the start. In many ways, I'm amazed it wasn't more ridiculous!
Riddles in the Dark was good. Well played. I was always worried about that because it works on paper but I feared that the long pauses while Bilbo thinks would have been boring. But I think they pulled it off okay.
I'm in two minds about Bilbo's killing of the warg and his sudden bravery at the end. On the one hand, I liked the idea that the Spider was his first victim and it really took him that long to work up the courage. On the other, I think it's a nice nod to how the Ring may be having an influence on him - pushing him to rash action. Let's not forget, the Ring is trying to get back to its Master, so pushing little Bilbo into a fight with orcs and Wargs may seem to it like a good path as it probably thinks Bilbo will die or be captured.
I hope there is a conversation with the Eagles in the next film. Or some explanation about them from Gandalf - I liked in the Hobbit book how it is explained that the Eagles do not like helping people because they are often shot down by elves and men. It nicely shows why they couldn't just fly them all the way there and back again. Eagles as cowards is how I like to read it, and if not for love of Gandalf, and hared of Orcs, they wouldn't have bothered with the battle of Five Armies. But, personal pet theories aside...
Over all, it was better than I expected. It was enjoyable and full of nerdy stuff. Beautifully shot and faithful in parts. I love Sylvester (and Sebastian) and will probably see it a few more times.