Certainly better than the first installment, Desolation of Smaug entertains. I think Hollywood has forgotten how to end the middle chapter of a trilogy. This, along with Hunger Games, ends far too abruptly to leave the audience with any sense of satisfaction. I'm no filmmaker but I would think it's possible to make a small epilogue to the episode you've just watched in order to round out the film so it can be enjoyed on its own (see Two Towers or Empire Strikes Back for reference).
Other than that major detractor, I thought they did a much better job at showing action sequences and developing characters in this film than the first. I was not only able to tell some of the dwarves apart, but I actually grew to like aome of them. The barrel sequence had a bunch of children in the audience laughing and enjoying themselves. What children were doing in this movie confuses me but I'm sure those spiders won't be visiting them in their dreams anytime soon.
Being an Arwen fan, I wanted to dislike Tauriel but I just couldn't. Also it's great to see Legolas as an archer of Mirkwood, these are not the softies of Rivendell that many mistake Legolas for in the Lord of the Rings trilogy. Actually there are moments where you'd think Bilbo was from Mirkwood, given that he's not acting at all like a hobbit out of Hobbiton. They've made the character a bit too brave and fearless for my taste.
Still a very good movie overall. I had fun.