The only difference between the two are what stat they scale with. They both have the same modifier of 95% of Spell Buff to calculate Damage. Yorshka's Chime, at 60 Faith, has 247 Spell Buff. Court Sorcerer's Staff, at 60 Intelligence, has 240 Spell Buff, because From Balance. Therefore, DMB is better than CMW, not because the spell is better, but rather because Faith Builds have better scaling catalysts than Intelligence Builds.