I have taken my children (they were 4 & 1) at the time. My son is also and early riser no matter what time he goes to bed he is up at 6:45 every morning! He was a trooper at
MNSSHP though. We had ZERO problems with him staying awake, no melt downs, and he had a great time. He conked out on the car ride back to our resort (we were staying off site at the time). I think that the next morning he slept in until about 7:30. My daughter had an absolute blast. We had a stroller for her when she got tired and took breaks for the both of them often. I think that part of the key to this was that we didn't do anything except for go to thepool the day of the party.
We were lucky to be able to virtually walk onto every ride and get all that we wanted to get done and be back in our room by 11pm.
The "worth it" part really only for you to figure out. For us it was worth it because we got to see
all of the characters in one night. They were all out and about. I have never seen that many characters out at MK at once. We got to see MK all decorated up for Halloween. We got to see a different parade that the general public doesn't get to see. We got to trick o' treat at MK. We got to ride the popular rides with little to no wait. We ate a LTT where the characters are dressed in costume. Watching my son and daughter dance multiple dances with Chip, Dale, and Pluto was priceless.
Read the hundreds of posts at
http://www.disboards.com/showthread.php?t=1045939&highlight=mnsshp
BTW, we are taking the kids back again this year dd will be 6 and ds will be 3. We all can't wait!