Unless you know this park well, some research and planning is necessary to make your visit the best one it can be. If you have no idea how to use Genie +, the virtual queue, lightning lanes, or even where the rides or characters are, you will be wasting a lot of precious time wandering the park and not getting much of what you or your kids want to do. There are tons of youtube videos that explain all of this, do example visits etc....watch a few!
We came to Magic Kingdom for pretty much 2 things: Mickey's Not so Scary Halloween Party, and Tron. We had ridden Tron in Shanghai Disneyland and loved it, so we were so happy to see it stateside. The Halloween Party would be the first Disney theme park event we would attend.
In our opinion, the Halloween Party was fun but probably not worth the extra cost. The allergy bags got us not much candy at all compared to the regular bags. The ride lines were great but there is not enough time to do everything. You have to choose between getting pictures, meet and greets, rides and trick or treating. There is no way to do all of them. The parade and fireworks were wonderful! What a catchy parade song.
Tron is the same as what we experienced in Shanghai. Everyone says it is too short, and it is, but the whole structure and being launched outside in full view of people outside is just such an amazing design. We still think it is a tad better than Guardians Cosmic Rewind.
Our home park is Disneyland and Magic Kingdom is so much bigger. Expect to walk double if not more what you do in Disneyland. In my opinion, the one thing that is better in Magic Kingdom (not considering rides) is the Customized Popcorn. I wish they would bring that to Disneyland!