Hi Julie!
I am right there with you when it comes to experiencing Walt Disney World Resort without the little ones. I remember when my husband and I did it for the first time, it was amazing to be together and enjoy the theme parks in our own way.
There are some differences as it relates to
Disney After Hours at
Magic Kingdom and the evening
Extra Magic Hours. I think that the biggest difference is that the Disney After Hours at
Magic Kingdom lasts a bit longer (from 10 PM - 1 AM). Also, because there are a limited number of tickets sold, that means that the crowds could be thin and could allow you to experience the attractions with minimal waiting. Extra Magic hours allows anyone that is a resort guest to attend, which could mean slightly larger crowds when compared to Disney After Hours.
Is it worth the extra expense? I think that no matter what you choose, you will create some extra rare magical moments without the kids.
Please return should you need additional assistance prior to your arrival.
Have a magical time!
Raquel