It's a shame, but many vendors leave by midday on Saturday, even when the weather is nice. Always seemed odd to me why so many vendors are in a rush to get back home when this is the biggest event on the East Coast, not to mention if you love your hobby, why are you in such a big hurry to head back, what you have a nagging wife who has a honey-do list that you just can't wait to get to?
The reason it's such a big deal with me is that us hobbyists know about this show, and attend Thursday thru Saturday, but the public that does show up really only comes on Saturday, their day off. I've gotten feedback from a few spectators in the past that were taken aback by the fact that they came to the show and it seemed everyone was pulling out early on Saturday when they were just showing up.
I plan to sponsor my own show in the future sometime. Rule will be, you are expected to stay until the close of the show at 5pm. If you leave early, you might be allowed next year as well, but spot preference and reservation will be given to those who stayed the course first. Just my two cents.