I've noticed that you can upgrade your accessories to either delicate or durable versions. It seems like the delicate is completely useless though. It costs a lot more gil, and the delicate versions seem to be weaker: the Power Wristband normally gives you +10% strength, the Durable Power Wristband gives you +12%, but the Delicate Power Wristband only gives you +8%, which seems like a downgrade. Is there any advantage to them? What's the point?
The purpose of delicate items is to decrease the amount of points the accesory uses.
Normally a Power Wristband uses 30 points so you can only equip 1 on a low level character with 50 points. However a Delicate Power Wristband uses 25 points so you can equip 2 basically giving you 6% extra strength or ofcourse allowing you to use a different kind of delicate item. The same goes for stronger items who by default take 55 or 70 points. Also making items delicate or durable allows you to have a greater variety of accessories equipped making your character suited for all kinds of combat.
A Delicate Power Wristband costs 25 capacity. When capacity is 100 (choose by crystarium) you can equip a 4x delicate power wristband. However, a 4x delicate power wristband will give you the vampiric killer effect, which will cure your damage by 5% of the damage you give every time you attack.
This is really cool.