^ yes. there is a security post at the entrance.

Ever since I spent the extra ten dollars for it I do it every time now. Well worth it. 

On nights the park is open especially late - or in the case of leaving the park to grab a meal later in the day - I love to take advantage of the fact that preferred is free after 8.  One night I got to the park around 7:40 and slid in for free.  When the attendants are gone, it is fair game.  I heard this from another guest and confirmed with staff at the main parking gate.  Most days, I just appreciate the extra steps and don't worry too much.  But hey, if its free, it's for me!