It wasn't for us, but we're all adults, so maybe that makes a difference. I think calling it a "party" is kind of misleading. It's basically just going to MK and there are some extra things going on in the park that you don't normally see: "rare" characters to stand in long lines to meet, and holiday themed stage shows, parade, and fireworks, all of which you'll have to get in place for early because of the crowds. There are cookies and beverages served around, but when we were there the entire park was so crowded that even trying to find the cookies was a pain, and the lines were always long there too.
All of that said, I'm glad we went and did it at least once. I am a Christmas nut, and so the parade, fireworks, and stage shows were all things I did love a lot. We're going this Christmas, and will be there over actual Christmas (last time we weren't) so we'll get to see the parade and fireworks without doing
MVMCP.
Now the Jingle Bell Jingle Bam dessert party at Hollywood Studios? Totally worth the money. Good food, meeting "the VIP guest", and outstanding viewing for the show...which is a ton of fun! And then a veritable snow storm on Hollywood Boulevard afterward. Oh, and those cool glasses they give you to wear that make points of light look like snowflakes or candy canes or whatever. And a complimentary Christmas ornament. Yeah. Totally worth it.