Everytime I go to an NFL stadium that seats 65-70K and then go to Neyland I'm amazed that UT can squeeze 40K more people in roughly the same size stadium.
Take the Bucs stadium, for example. The lower bowl on the sidelines has about 60 rows, and the upper has 30 rows. That's about what Neyland has, but all around. I guess that's the difference. That and chairs vs. bleachers.
Picture taken yesterday. I photoshopped some of the sections to green grass. But while I was taking this picture they were putting some sod down. Neyland Stadium by 00Accord4cyl, on Flickr