My pre-teen son and I may be the only fans to have been to both the game at OU and vs. Baylor this season. (I know what you're thinking--don't attend any more games this year!) Anyway, here's my perspective...
I was disappointed in the crowd, especially after I over-hyped Hilton Magic to my son and what the noise level was going to be like if the game was close. This hurts to say, but the OU crowd had a louder peak crowd noise while the home team was on defense than Hilton had on Saturday. How I judged it--son with hands over his ears at OU, no hands on ears in Hilton. Hilton got louder in spurts throughout the game than OU's crowd would, but Scott Drew called his timeouts as soon as the crowd stood, and then like lemmings the crowd sat down during the timeout.
I was really disappointed with people leaving with minutes remaining in the game. With all the comebacks in Hilton's history, that blew me away.
The introductions at OU and ISU are so drastically different. I can't say it has any bearing on the crowd decibel level, but OU's is much cooler--total darkness, similar hype video, 15 foot flames shooting out of both goals.
One last thing about the Hilton crowd. The worst thing for both the crowd and the team was that ISU got up big in a hurry. After that point, both seemed complacent and almost surprised that Baylor could get on a such a big run--until it was too late.