I think that Disney popcorn is some of the best in the world. I am not sure if it is the environment or if Disney uses a better grade of popcorn, but it is some good stuff.
I always save my popcorn container, no matter if it is the regular cardboard container or the souvenier bucket. I bring them all home and re-use them.
The souvenier bucket will usually hold a microwave bags worth of popcorn, and I stuff the bucket into a tote and sneak it into the movies.