I realize this is my first post so be kind, but I honestly think the best queue management is at Universal Orlando.
They only sell a limited number of express passes per day based on park attendance. Then there are the folks that stay in the on-site hotels which get the express privileges with their room keys.
The ride attendants are very conscience about the lines and flow for both the stand by queue and the express. Express queue's are let through a few groups at a time, but are capped at usually around 10 to 12 riders per cycle, and then the stand by queue is ushered through. The system seems to work very efficiently.
The peak season tends to draw longer wait times but I have never seen a wait longer than 60 mins for any attraction in the park. And when the wait is 60 mins for the stand by queue you better bet you are going to wait close to 25-30 minutes in the express lines.
Most of the time if you go to the park anytime that is not June or July you are looking at 30 mins or less for any ride in the parks using standby. Many times especially in Sept, Oct, Nov, I find that you can just walk through the queues and get right on even during weekends.
On top of that nearly all of the queue's are themed for the ride, are indoors and airconditioned. There are a few exceptions, but for the most part it makes the waiting less mundane to have neat goodies to look at while waiting, and to be cool and not have to deal with the sweaty funk of an outdoor line.
All that being said, I wish HHN was run at anywhere near the efficiency of the daytime park operations. Last year at one point the wait for the Nightmare on Elm haunt was over 3 hours. Express pass is the only way to see HHN or spending $$$ and getting the RIP Tour. I think that the parks really should take a look and consider a strategy for improved effiecency for this event.
I havent been to a Six Flags in over a decade, and after hearing about the price and hassle of their systems in this thread, I will probably never go again unless something is done about it, so thanks for the information.