Crowd level with Orlando Informer Meetup

We are considering visiting Universal at a time when the Orlando Informer Meetup is offered. They say that they sell only a limited number of tickets and only those with tickets are there from the normal park closing time until 1 a.m. My question is whether the crowds are really less after the day guests leave or whether it is better to visit on a typically 4-6 crowd level day and use Early Entry. (We are staying on property)