WARNING: Full spoilers below.
I've only seen this film once so these are only my first impressions that might easily change with repeat viewings but overall I didn't enjoy this as much as the first film. There are many great scenes within the film - Gandalf's quest, Lake town, Bilbos meeting with Smaug but then there are many more additions, alterations and omissions from the book, which aren't necessarily a bad thing in themselves and some of them do work (legolas' inclusion, Bards character expansion, laketowns expansion) but a lot of them don't. The changes to the encounter with Beorn, the journey through Mirkwood, the character of Tauriel and most of all the finale of the film which involves most of the dwarves and Bilbo 'facing off' against Smaug were simply too far from the source material in intent and tone.
In regards to that last one, I appreciate the fact the screenwriters wanted the Dwarves to confront Smaug more directly rather than leave it up to Bilbo as it is in the book as otherwise this might portray them as cowardly to the audience, but then the purpose of Bilbo (in the film here) is to steal the Arkenstone, which he could have achieved whilst Smaug goes into his rage and destroys lake town before being shot down by Bard which could have been the climax. The dwarves could have even helped him steal it eventually to give them some function rather than make them attempt to destroy Smaug. Instead the film ends on a bloody cliff-hanger, and a very tantalising one at that which certainly builds anticipation for the next film but left me feeling majorily unsatisfied with the ending of this second film.
Also the fast-paced nature of the film which you commended MovieBob I criticise, because it was too fast too often. None of the places we visited or new characters we met was given a great deal of time to play on screen except most notably Tauriels moment with Kili (that was also another issue of mine: the Tauriel and Kili romance, I mean they even seemed to have fallen in love after just two meetings!) There were not nearly enough 'breathing space' moments and the action scenes went on too long (as it did in the first film with the escape from Goblin town). A faster paced film can work but I just don't feel it suited the hobbit material and I much preferred the slower pace of the first film because that time is given to soak the atmosphere of a place in and its more in keeping with the ambling nature of the children's adventure story that is the Hobbit book. Perhaps the extended editions will slow things down as they did so well for Lord of the Rings.
Oh and yeah, considering its called 'The Hobbit' there was not nearly enough Bilbo in this movie at all ? his stuff in Mirkwood was cut down to the bare minimum, again tying in with this 'faster pace' which I didn't agree with and in Lake town he plays barely any sort of role whatsoever.
Just overall I have so many more issues with this film than the first at least upon first viewing. I'm willing to give it some benefit of the doubt and perhaps things will converge more smoothly in my mind upon repeat viewings but for now it was disappointing to me.