One thing I noticed when we recently went to California Adventure is that the park got very crowded with teenagers at night. We went on a Friday and while the daytime had a family atmosphere, at night there were teens running amock, particularly at Paradise Pier.
While I have nothing against teenagers, it was very noisy and they were running all over the place. We had a group on TOT that screamed the entire time. I couldn't hear a thing that was going on on the ride.