I can only estimate at numbers, but the park was PACKED this previous Saturday for a Kirk Franklin concert. To be honest, in the 10+ years that I have been going to the park, I had only ever seen it that busy maybe once or twice (and both times were during Fright Fest). Their last (paved) lot was nearly full and the midways were packed with people. However, the park was handling it quite well. Trash cans were staying emptied, there was lots of entertainment out and about, all the coasters were running two trains, essentially no trash on the midways, they were keeping the line on their new toy (Apocalypse) moving with almost no stacking... I was very impressed. Operations wise, the park was running like a first class venue.
For those that didn't know, the park moved to a new(er) Flash Pass this year. Many other Six Flags rolled out the new water park Flash Pass that utilizes a RFID wrist band and reservation kiosks. Six Flags America is using this RFID stsrem for both the water park and the main park. The downfall is that you don't get the cool Q-bot so you can see the ride times of all the rides and reserve from anywhere, but the positive is that you can use the same (low price) system for both the dry rides and the water park. It also makes it REALLY easy to see who is using the system (because of the bright yellow bands). An on a day that was so busy, I was surprised to see so few people utalizing the system. I guess until SFA is that busy all the time, it will probably stay that way. Then again, the water park always IS that busy, so maybe it will catch on sooner in the waterpark.