I disagree on busier. It's a limited ticket event that sells out most nights (sometimes minutes after the party starts but still a sell out crowd). Now I do agree that different parties have different crowds and when it's a ride everything crowd it will feel emptier with long ride lines but the opposite and it just feels like you can't escape the crowd.. The busiest parties I've experienced are the one following a party that had horrible all night rain. Disney will give out tickets and load up the next party past it's normal cutoff point. Those are packed full...
I tend to like the people who attend the weekday parties, especially the earlier in the week. They just seem less rude to me. Most people arrive or leave on the weekend so I think they are either in a "I'm here, i'm getting my money's worth" start or a "I'm leaving, I'm doing everything I can like a maniac" attitude..
i've seen more than a couple parties with bad weather just ruin the experience so I recommend you go as early in your trip as possible. This way if something goes wrong, you might be able to attend another night before you leave.