[ratmanscoop]

It's entirely possible that express pass customers get preferential slots to regular guests, but that's just conjecture on my part. Perhaps only 90% of the ride's potential capacity gets allocated such that where a booking placed by a regular guest may be 5 hours from then, a guest with an express pass may get a slot 30-40 minutes away.

My suspicions regarding this are that there physically isn't room in the (to my recollection quite restrictive) plot that Twister occupied to have a queue area suitable for containing multiple hours' worth of queuing guests, so making the ride reservation-only makes sense.