For how much time it can take to gather each piece of a complete set (such as the Acolyte or Cavalry set), do you think that each piece should offer a bonus if you complete the set? As it is right now, I love completing these sets, and, for at least a few levels, they're better than the normal gear you can buy from a vendor. But often by the time I or anyone else do finish collecting them, they've often lost their edge over vendor--and especially GC--gear. So I'm thinking they should include a set bonus that acts as an incentive to keep wearing them, besides the fact that they tend to look nicer than the standard gear we can buy.

I'm not talking about a straight up stat boost, either, but more along the lines of giving each class that the set is meant to be worn by a unique, specific trait. Something along the lines of this:

Acolyte Set
THM- Every time Fire1 hits a monster, there's a 10% chance for Fire2 to have no cast time and cost no MP

CNJ- Every cast of Cure1 has a 20% chance to double its potency, and remove a negative status effect on the target

ACN- Every time Miasma deals damage to an enemy, there's a 5% chance that Energy Drain can be used without consuming an Aetherflow

Those are just examples that I threw together in about a minute, but you get the idea. I'd also go against adding these bonuses to crafted pieces if only because you can meld materia onto them. This way if you want to go for the best stats, you can use the crafted armor, but if you want a unique trait, you can use the dungeon gear.