Quote Originally Posted by Alberel View Post
Done properly, horizontal progression on gear does still improve your combat abilities but by way of versatility and utility instead of power. FFXI is a perfect example of this as many pieces of equipment had effects on them that modified your skills. The result was that changing from one gear set to another caused you to lose some effects and gain others, thus it balanced itself by nature of the effects being mutually exclusive and some content would require you to use certain sets over others. Unfortunately the gear-swapping in FFXI ruined the whole concept as everyone was able to gain the benefit of every set at once but the theory was sound.
Yes, unlimited in-combat gear swapping made FFXI's Horizontal Gear Progression system a Per Ability BiS Vertical Progression system though few are willing to admit it. FFXI also has some minor trouble with gear lifespan where some pieces ended up BiS for far to long.