The EQ in the upper mids (probably between 5k and 10k) on the quad/bluray version is emphasizing the upper harmonics of the guitar riff - it's the same take, same guitar,etc. It basically matches your comments about the mastering on that album being more trebly.
If you have a program like Voxengo SPAN (which is freeware I think) you can load the two files up at the same time and compare the frequency response differences.
If you have a program like Voxengo SPAN (which is freeware I think) you can load the two files up at the same time and compare the frequency response differences.