OSU's offense is #2, behind OU's and averages significantly more yards passing (significantly less rushing, though). Their strength of schedule is 49 vs. OU at 71. OU's wins over WVU and ISU are far less impressive than OSU over Michigan and PSU. Similar to OSU, they've struggled against some far inferior opponents (Army in OT, Ok St by 1, Texas Tech by 5).
Obviously, OSU's one loss is way, way worse, but they lead in pretty much every other category, although the "eye test" is obviously subjective. I'm biased, but if the season ended today, I'd put OSU in by a nose. However, I think OU can help themselves much more this weekend than OSU can with a win, which could (probably should) put them over the top.
You also have the common belief (that you seem to share) that OSU would have a much better chance against Bama, which could factor somewhat into the committee's minds. Also, if OSU is left out, that would make 3 years in a row the B1G champ misses the playoff. Or the 31-0 debacle vs. Clemson could still have some slight influence. Who knows.