I agree with all of Lena's thoughts.
I would add...
I also really wish they would have had more time in the arena. I wish they would have shown Katniss' utter desperation for water in the beginning. It moved a little too quickly for me, but then showed her sleeping in trees a lot.
I also really wish they would have developed her relationship with Rue more. I felt like they hadn't had enough time together yet, in the movie, to warrant Katniss' drawn-out grief. Yes, I know she was also grieving someone who was kind of in place of her sister, but I still felt like the relationship hadn't been given enough time.
I liked the addition of the berries to Seneca's ending. Thought it was an interesting touch in the movie not found in the book.