It would seem that standardized scoring profiles at the 25th percentile level can serve as an indicator of how uniformly rigorous a college can be. Caltech, for example, which reports a 25th percentile SAT score (EBRW + math) of 1530, can expect its students to assimilate material throughout the curriculum at a somewhat higher level than, say, Harvard (1460) can; Williams (1410) can design a curriculum more uniformly rigorous than Bates (1210) can; and Harvey Mudd’s reputationally high rigor seems substantively dependent on its extremely high 25th percentile score (1490).
Of course, schools with internal academic divisions or honors programs would be more difficult to analyze in many cases because isolated standardized scoring profiles may be unavailable.
Note that all colleges mentioned in this post were chosen from the higher levels of academia. The comparisons, then, should be considered on a relative basis only.