I have seen mixed reviews.
I think that it has been extended for only the Christmas party nights, ,so you would have to buy the Xmas ticket (about $55) plus the dessert party ticket ($25). Keep in mind that during the party, everyone gets free cocoa and cookies in the park.
If it is offered other nights, keep in mind that you get a table to see fireworks and sit and you get a selection of desserts (I have heard some people say that they aren't replenished often and if you get a late seating time things are picked over and the tables are very squished together).
The location is in Tomorrowland off to the side of Mainstreet so it is not a dead on view of the fireworks but is still good. If tinkerbell is flying that night, she lands on the roof of the location of the dessert party.
Other things to keep in mind.....
it is difficult to see the parade from the location, so don't count on having much of a view of it.
How do your kids do with a bunch of sugar late at night?
Do you have the Dining plan? You will be having multiple desserts a day included with the DP.
There are tables about 50 ft. away from this location where anyone can sit (on the side path toward mainstreet). You could go get $100 bucks worth of treats at the bakery or candy shop and sit there or on mainstreet and have your own dessert party (kidding about spending that much on treats, but it's close to the cost of the party for the family so it's not that much of an exaggeration).
Most reviews that i've seen, the people said it was nice but they wouldn't do it again.
Ask yourself if you would rather have the $100 at Xmas time.
If I were you, I would get some ice cream on Mainstreet or a treat at the bakery or candy shop or some fun glow toy and hang out on mainstreet or the upper level of the trainstation.