In my opinion, going to the MK all day and staying, and paying , for the party ticket is a waste of tickets. We use the morning of the party to sleep in, swim and eat a decent meal, then go to the MK at 4 and enter with our party ticket. Just the way it works the best for us. Buying tickets is the major expense of a vacation to WDW, so I plan out the days I want tickets for and subtract out the party days and use only party tickets to go to the MK. We usually attend MNSSHP twice on our October vacations and entering at 4 gives us 8 full hours in the MK, enough that we feel we have done all we want to do there.
Just re-read the OP. Someone answered it correctly already, I of course went way off topic! Sorry! However, if you plan on going to the party it is fun!