My brother and I were in 245 for the Mizzou game. It was moving so much that we both stopped jumping and pointed out the movement of the rail in relation to the field behind it. I understand human perception probably over-exaggerates, and i would say the 6-12" is an over-exaggeration, but I would bet a lot of money that it moved no less than 4". 5-6" is probably closer to accurate. I've never seen anything like that before, and it was definitely unsettling. We were about 6-7 rows up, and the ground under us felt like it was moving a good 2-3".