I've been toying with adding Stat requirements to some item (weapons & armor) to be used effectively, and bonuses if the character's stats exceed the requirement.
Something along the lines of:
Shortbow has a minimum strength requirement of say 30 (representing the draw weight of the bow), which sets it's basic damage and range. Maximum of C critical. Within 10 feet it's +10 OB, +5 to 30 feet, +0 from 31 to 60 feet, and -1 OB per foot after that?
A composite recurve bow has a minimum requirement of say 75 (again representing a higher draw weight) which also set's it's basic damage & range. Maximum of E critical. Within 25 feet it's +10 OB, +5 to 50 feet, +0 from 51 to 75 feet, and -1 OB per foot after that?
Similar concept for armors, but when exceeding the strength requirement you can reduce the MM penalty by some amount.