Ok heres the lowdown from a vet of both parties.
MNSSHP is wonderful if your a Halloween person. Much better than MVMCP . That being said , MVMCP is a delight for those wanting to kick start the holidays . Snowing on Main st is one of those life moments you will never forget.
Both parties are not what that used to be in regards to lines/crowds. While many times the lines will be shorted, especially at the end and beginning of he party, Main will be packed as will Character greets.
Cookies n hot coco or trick or treating is cool , but hardly worth the prices alone. The reason to go is the atmosphere.
You cannot be seated at an ADR after 7:00 if you are not a party ticket holder.
You can get you ticket band up to two hours before the start of the party , this way you do not have to fight the crowds exiting at closing.
If you just want to see snow , you can go to the back of the park on SPlM SPM or PP, and just wait till they usher you out. Then you will catch the snot on the way out while crushed in the entering and leaving crowds...
All in all both parties are , at least a once in a lifetime must do for everyone!