In 2003 we did the sold out Halloween night one. Then in 2004 we did the first one on 10/1. The non sold-out party was such a different expierence from the sold-out one. We only did 1/4 of the things we wanted. It was hard to walk anywhere. The Halloween attractions were hard to get to as well. However, the rides still had short lines (go figure). If it was a choice between no party and the 10/31 party--- I would go 10/31. However, if I had another night to pick from I'd go that route instead. Also, the 10/31 tickets do sell out. I have a feeling w/ what they've fetched on ebay this last year. They may sell out sooner this year, as some people are may pick them up for resale purposes only. So, if you are going 10/31 be sure to get your tickets early.