i think you will get a lot of mixed reviews.
We have done it twice now and enjoyed it. we see it as more time in the park more than anything else- with that special holiday flair.
We won't wait in line more than 20 minutes for anything- so we aren't big show people- we skip most of the holiday shows, since some had large lines to get in and a long wait (at least back when the theatre was open in TL). We do really enjoy the parade though. We usually ride rides with no lines during the first parade, catch holiday WISHES and then see the second parade, which is less crowded (10:30pm). The hot chocolate and snacks are fun. we enjoyed watching the dance parties too. Overall, we just found it fun to get some extra time in the park, since the MK closes at 7 or8pm on the other nights in early December when we go.
We will probably do it again this December too. We typically prefer the weekday parties, the weekends seem to draw bigger crowds (more locals etc.).
do it once and see how you like it.
and if you don't have a length of stay ticket, the party is a good way to get into the MK at 4pm and do something else that am (resort dining, DTD) and still get in park time.