I agree with the poster who said Memorial Stadium in Lincoln is overrated. I know their fans get super excited for the "tunnel walk" but it's kind of lame actually. Only been to one game there, but their fans were really bi-polar toward their team/coaches. Of course, it was in 2007 when they almost got run out of their own stadium by Ball State, so that may have had something to do with it.
Texas is the only other Big 12 stadium I've been to, back in 2002. I had to be in Austin for a weeklong tranining session, so I scheduled it to be the week of the ISU game and met a fellow Clone fan down there. My friend had some cousins (UT fans) coming up from San Antonio, so we tailgated at their RV before and after the game. I had to park somewhere south of the stadium and walk to meet them, but nearly every single tent I walked by, some UT fan offered me food or drink, wanted to talk about the game, or sympathize with me over the previous week's beatdown at the hands of OU.
During the game, we sat in the middle of a large donor section and didn't have a single bad word said to us throughout. In fact, we were going out of our way to be extra quiet for fear of upsetting someone when one of them said, "it's ok for y'all to cheer, we don't mind." Also, most of them were telling us how they wanted to trade Chris Simms for Seneca straight up. The weather was cold and rainy, and the game wasn't very exciting, but it was still a good time.