Enchant Weapon - Potency: Strength has the following effects: * Increases attack power with melee weapons: - Warriors, death knights, druids in all feral forms, and paladins gain 2 melee attack power per point of strength. - Rogues, hunters, shamans, mages, priests, warlocks gain 1 melee attack power per point of strength. * Improves block value by (Strength / 2), rounding down, for all classes capable of blocking warrior, paladin, and shaman). * Increases parry rating for death knights by 0.25 parry rating per point of strength. Strength does not affect the chance to land a critical strike. Strength does not improve the chance to block.
Conclusion: - even tho both enchants have "potency" in their title, they are quite different - for Warrior & Paladins tanks, Potency is better. Death Knights have runes and Druids prefer agility. - from a dps point of view, Greater Potency is better.