I agree, the E-ride nights are totally worth it. It is such a great feeling to see the mass exodus of people while you can stay and ride for another few hours. It was great going on Buzz Lightyear, showing the wristband, and being let into the queue. I remember some other guests who did not purchase the e-ride night tickets trying to get into the line and the cast members had to explain it and not let them enter. I kinda felt bad for the cast members -- they take a lot of abuse from some people.
Another great benefit of the e-ride night was that characters were available for photos and there weren't mobs of guests.
I know that not having done this before, you may feel a little clueless about it, but when you get to MK, ask a cast member and they will direct you. Everything is organized and set up really efficiently. You'll get your wristband and you'll be set for the night. ENJOY IT!!!!