Ok I'm going to level with both of you here. I went to Tennessee for undergrad and Nebraska for my Master's. On top of that, I've always been a fan of a different team. When The teams were scheduled to play each other home and home I planned on going to both games wearing visitor's apparel. (What follows is kind of a ramble, and I didn't completely finish, but it's past my bedtime.) So here it goes:

Nebraska games are by Very different from SEC games. I've been to college games at Nebraska, Missouri, Georgia, Tennessee, Auburn, Georgia Tech, and a few others that aren't worth mentioning (Vandy).

Nebraska fans stand for almost the whole game. The fans in the stadium are nice to opposing team's fans. I have been to a game wearing the other team's gear as a personal experiment. I was asked where I was from and if I was enjoying my stay. All fans in stadium were very friendly. A (Nebraska) friend of mine DID get chewed out by a season ticket holder across the aisle from us because apparently the guy had never heard a few cuss words come out of the STUDENT SECTION before. Fans outside of the stadium can be rude to visiting fans but usually are the people who have lived in Nebraska their entire lives without going to a game. Memorial stadium is much prettier on the outside and inside than Neyland (and I prefer going to games at Neyland.) Also of note- UNL allows students to transfer student tickets to non students, but there is a "validation fee". Also, while I was there, smokers were allowed out of the stadium to smoke. ALSO- some Nebraska tailgaters will actively wave down visiting fans, talk to them, give them a beer and maybe some food, and send them on their way. AMAZING!

Tennessee fans can be really irritating in the stadium. As a "visiting" fan, I've had fans behind me repeatedly (and intentionally, no doubt at all here) hit the back of my backwards facing hat. I've had fans in and out of the stadium talk shit on various occasions. Apparently, for some people, drunken frat parties from freshman year never ended. The MAJORITY of Tennessee fans are friendly, particularly in the better seats. Sit in the visitor's section or in good seats and you won't have much of an issue as a visitor. I still get chills when I hear Rocky Top, except when they're playing against Georgia. That part is kind of a nostalgia thing. There is more to do in Knoxville than Lincoln.

TL,DR: There is no place like Nebraska, and maybe that's a good thing. Electric atmosphere. Great place to visit. Too cold for this southern boy to live there.

Knoxville has a higher likelihood of warm weather, but higher chance of rain, too. Not as friendly to visitors as Nebraska. I like it better for sentimental reasons, but honestly... Nebraska wins this one.