Hello Anthony!
I am kind of biased, because I love
Mickey's Not-So-Scary Halloween Party so much! Halloween is my jam. I love dressing up in costume with my family. Both the Halloween and Christmas parties offer similar extras such as a special parade, special fireworks, and special Character Meet and Greets. These are things exclusive to the parties and the party theme. I prefer Mickey's Boo-to-You Parade over Mickey's Once Upon a Christmastime Parade, and I also love the often-misunderstood Disney Villains.
My young children love this party, because of one word...CANDY! Even though their eyes are bigger than their stomachs, they love skipping down the path, saying trick-or-treat, and watching their bags fill up. My 2-year-old had an absolute ball last year, and yes, I admit, I let her have candy for dinner, and she was so happy.
However, if you are an absolute Christmas lover, then Mickey's Very Merry Christmas Party offers many magical holiday delights. The gleaming icicle lights on Cinderella Castle are breathtaking. And the mood and atmosphere are indeed merry. I couldn't stop smiling, because everything was so cheerful.
With a 3-year-old, I do not recommend touring another park in the morning. I would sleep in that day and do relaxing things around the Resort. You can enter the Magic Kingdom at 4:00 p.m. with a party ticket even though the party does not start until 7:00 p.m. If you do not have a party ticket, then you can still enter Magic Kingdom park in the morning with a regular theme park admission, but you cannot stay in Magic Kingdom park once the party starts. Those with party tickets will have special wristbands.
If you have any other questions, please come back and see us real soon at the Disney Parks Moms Panel. Have a ghoul-astic or ho-ho-mazing vacation!
Tania