C +
I got the sense of a story stretched out to cover 2.5 hrs. For example, the Laketown scenes (after Smaug's defeat) could have been condensed. The plot also seemed paper-thin featuring 2 hrs of battles and fighting over the mountain and not much more that. The fight scenes were exciting but got boring and tedious.
The highlight for me was Galadriel vs Sauron.
What are her powers exactly? Is she stronger than a Valar?