I saw Super Bowl VIII in 1974 at Rice Stadium. I also saw a Rice-A&M game in 1978 there. I was only there because I had an ex brother in law who was going to A&M at the time and my family went. Funny story, I rooted for Rice in the game (they lost naturally, and there were more Aggies in the stadium than Rice fans) and my whole family was mad at me.
This stadium has gone unneeded at a 75k capacity for decades, since the Astrodome was built. Other than the Super Bowl in 1974, sadly, nothing of importance has taken place there. No shade at Rice, it is just that the times changed a long time ago that a private, High End (Ivy League quality) educational university will no likely longer field an elite football program that would require this large a stadium. This is a really good move on Rice's part.