This movie sucks, rocks or is merely adequate depending on your point of view.
It rocks because it has Benedict Cumberbatch as the voice of Smaug, and the personification as dragon comes into play very well in what he does. The visuals are stunning; particularly Under the Mountain and Lake Town make me feel like I'm in Middle Earth. The musical score, costuming, casting, and cinematography are spot on. I am *IN* Middle Earth. All those immersive elements from the first movie remain in play. When he gets screen time, the actor playing Bilbo is particularly good, and the 'side plot' of Gandalf actually is welcome and makes sense...seeing where he goes rather than constantly vanishing for prolonged periods of times makes for a much better movie.
Now...as for the rest of it, it depends on the mindset you go into in this movie...
If you're viewing this movie as the book, "The Hobbit"...it's frankly just awful. The first movie was dissonant, and you knew, instinctively, that it should be two movies....not three, and wondered what they'd have to throw in to justify it as such; which we get. A romance. Super mario brothers dwarf barrel edition. Lake Town Board Walk Empire. Homeland Orc Interogation. What If? - The Dwarves had actually tried to fight Smaug instead of cower like the little worms they were?
Oh and a bit of spiders where Bilbo only does a tiny bit. And a werebear in there.
The worst thing is that the SPIRIT of the book just isn't there. The Lord of the Rings was awesome, albiet not perfect, because it captured the spirit you felt (at least that the vast majority of us felt) while reading the books. It varied from the plot a little, but where it did made things much better; filling in holes for Gandalf, caring who Aragorn marries at the end of Return of the King...things like that.
BUT if you view this movie as a prequel to Lord of the Rings the Movies...
It is merely adequate. And it makes a lot more sense that way, because it sure FEELS like Lord of the Rings. Sauron is showing up way earlier than he should. Everyone knows about him and is waiting for him and it feels like he's been hiding for a hundred years, not millenia. It is also essentially a retread in many ways of the Two Towers including anti heroes (Wyrm Tounge the Lake Town Master's counselor, Faramir/Beorn human politics, Gandalf in a swinging open air cage, Legolas the Ninja Elf) etc. It's a copy of an original and a SHARP copy, more importantly it sets up the third movie to be AWESOME and something we haven't seen before. If I were to give letter grades using this format, rather than emulating the Hobbit, I'd give 1rst: B 2nd: C and likely 3rd: A.
Oh....one more thing...Orcs. Everywhere. And I mean...EVERYWHERE. In Laketown. In the woods. In the mountains. Near the werebear. In the river. Near the mountain. The Orcs are magical. The orcs can teleport. The orcs can clone themselves. No matter how many you kill, there are more...always. Also, they now come equipped with magical Sauron Cloaking spell.