If artifacts is going uber useful, then also put restrictions on them so they cannot be used by anyone. Heavy weapons should require a certain amount of strength without causing penalties (sort of like how it works in FONV - try using a minigun with strength 2), or Skeleton Key to require a certain amount of agility. Or even vice versa, a "Hat of Luck" (lol) can boost your luck to 7 but not beyond, so luck = (luck + 5) max 7 makes it not all that useful for already lucky characters.

There could also be significant cost to obtaining them. Like, go kill these three people. Problem is, they are the best followers in the game - do you *really* want to sacrifice them? Or, kill this dude. Except, he will be the one who gets you the advance you need in the fighters guild. Now, I like to play my character, and trying to be good, I can't allow him to go about killing people to obtain some powerful stuff. But from what I'm seeing around here, many don't give a damn about role playing, so unless there is a hurt that affects the player (rather than just the character), it's not going to work.

Perks, the way they could add conditional customization to different aspects of game-play in Fallout 3, would bring uniqueness to anything that custom texture or enchantment could never bring.

If you had items that would add their special conditioned perks to you whenever you equipped that item, you could make *really* unique items.

Conditional perks can check the characteristics of the wielder, the characteristics of the target, the characteristics of the environment and add new effects to the attack of the weapon, or the defense of the armor, or the behavior of the item, depending on those conditions.

There would be almost unlimited potential for customization to create a really unique item that would keep its uniqueness how ever you grow in levels and find new items.

You forgot to add "Item Perks" in your customization styles for the items, so I just selected Other.

Edit: I suggest you add the Perks choice to the poll and add my description about them, to see if people would change their votes to include them or not.

By the way you can follow my signature link about the http://www.gamesas.com/index.php?/topic/1107940-perks-they-can-make-each-play-through-a-unique-experience to see what I had suggested about implementation of them quite a while ago.