Sooners are more likely to justify cheating in the name of winning, since "everyone does it." This is not to say that Aggies don't have a dose of this, too, but it hasn't been as strong as the Sooners variant. The cheating is strong in this one (OU).
Aggies are more likely to be delusional about upcoming seasons, and/or be uber-racist, sexually-repressed, and just weird. There are sexually deviant things that Aggies are known for, or at least there are persistent Aggie fables. (I've gotta hope that) Sooners just would not do that stuff.
Which one (still) has the Corps, buries dogs on its field, and chased off other cheerleaders? Case closed.
As for arrogance, it's a personal trait, and not connected with which school you go to. The arrogant ones were that way well before they went to College Station, Waco, Austin, etc.