It's more exciting and better paced than the first film, but it still has the same problems, the biggest being unnecessary subplots shoehorned in just to pad out the run time.
Do we really need to know what Sauron was doing during The Hobbit? He was the focus of LotR - that was the story where he was the main villain and he was given a back story and a presence there. The story here should be about Bilbo, Thorin and Smaug, which only comes into play nearer the end.
I have a mixed reaction to the newer cast members. Cumberbatch does an excellent job of voicing Smaug and the CGI design is decent enough, though wouldn't a realistic model have been even more amazing? Come on, Jurassic Park did it 20 years ago, and LotR raised the bar of special effects, why shouldn't The Hobbit be trying to do the same? (Filming in 48 fps doesn't count - soap operas have being doing that for years).
Also new is Tauriel, a character specially made for the film to address the issue of lack of female characters, which is commendable, but I feel she, like a lot of things, just feels like a fifth wheel to the plot. A romantic subplot between her and Kili just doesn't add anything.
Personally I found Stephen Fry's character hard to take seriously - he's a comic actor, and I couldn't tell whether he was trying to play the role straight or not.
Overall, it's still more fodder for the fans, but I remain adamant as ever that The Hobbit could have been a great film, or two films, but makes a mediocre trilogy.