To me, the lingering question of how 2004 Auburn would've fared against 2004 USC is more interesting than the question of 2003 USC vs. 2003 OU or 2003 LSU. 2003 USC wasn't nearly as good on the lines as 2004 and they weren't the same caliber as LSU or OU, despite how the roles reversed between them and OU the next year. But 2004 AU, despite not being as impressive at times as SC or OU, had great lines, an NFL secondary, and an NFL QB in an offense that utilized a lot of dumps to fullbacks and TEs, i.e. exactly the kind of offense that could make progress against SC's defense sans a mobile QB.
I don't know if AU could've beaten SC in 2004--I don't know if any team was going to beat them that night--but they matched up well with them. I remember TrojanMark admitting as much here years ago.
2010 AU was weird. That roster was really hit and miss, with a lot of glaring holes/weaknesses. But their standouts.....damn. That OL, QB Cam Newton, and the two DT's, Fairley and, um....the other one not named Fairley...somehow, someway were enough on their own to cover a multitude of roster weaknesses elsewhere.