We went to the Season Pass / Discover Card Sunday ERT event in June, and it was nice. They started to pass out wristbands at a specified spot in the park (actually in the section of the park where the two coasters ERTs were being held at) about 2 hours before close. Since SFOG closes at 8pm on Sundays, that meant that we got our wristbands at 6. We rode other coasters and walked around until the park officially closed at 8pm. Then, we rode the lesser-intense of the two rides, Dare Devil Dive once and immediately went over to Goliath, the other coaster that was open for the 2-hour ERT!
It was not as busy as I thought it would be! I was able to ride it 14 times in a row in under 1hr and 15 minutes. I could have ridden it another 30 minutes and gotten close to 20 total laps on there, but my girlfriend was not feeling well from the pizza we ate, so I did not want to make her wait for me to finish riding!
Tips...
Eat at least an hour or two before the ERT. Drinking some extra water is great. To maximize ride time, use the restroom about 10 minutes before the ERT begins. Of course, you need to remember that general public may still be in the line for 15-20 minutes of the ERT since they can normally still get into line right as the park is about to close. Keep your hands up the entire time... and have lots of fun!