I loved everything about Smaug and his scenes.

One of the things I liked about him was that he was not all powerful. He was so big that the Dwarves were able to use their knowledge of Erebor to elude and draw him in. They way that they used water against him made me believe for the first time that an organized campaign against him by the united houses of the Dwarves might have a chance of succeeding.

I like the design as well, the way Smaug uses his winged forelimbs to walk and as hands. He looks less like a winged alligator. less dumpy and more fantastic to my mind.

The chase scene in Erebor does go on a little long for my liking and I dislike Thorin standing on Smaug's snout but that is PJ for you.