Yes there is a line. It's recommended to buy tickets online
Yes, there is a line often -- depends on the event and the time how long the line is. Please be nice to the staff regardless. You can get tickets ahead of time, but that doesn't guarantee you won't wait in line -- again, depends on the event and the time. Unlike some pretentious places, if there's a wait, it legitimately means they're at capacity.
Can book tickets online which is easy. Was a queue midweek for Dirty Circus cabaret.
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