Yeah like I said, it depends on the theater. The seats were not reserved, the wristband was basically to let the theater know they checked your ticket and that you would be guaranteed a seat. There were only enough wristbands as seats, so once the wristbands were gone, they knew they would be at capacity and would start turning people away. Where that seat was depended on where you were in line, for the people in the front of the line got to pick better seats. So for TDKR I got there 3 hours early, (could have been 4 hours early can't really remember), and once I was in line, I only left to go to the bathroom, and had my place saved by my friends. I definitely didn't go hang out elsewhere to kill time.
When I saw TDK I got there 7 hours early, and was 2nd in line. But that wasn't a pre screening, it was just the press screening for Austin/premier.