I was recently deep in a geek discussion about the Episode 7 trailer lightsaber, mostly criticizing its flaws. Since I'm hooked on this system, I eventually came up with a way to describe it in game terms. The result was an item quality that is the reverse of Cumbersome or Unwieldy (I think that's the one for the double-bladed). It's reverse, because it sets a maximum rather than a minimum.
Item Quality: Ridiculous [Ranked]: If a character's Intellect score is higher than the value of Ridiculous, that character cannot understand why anyone would use such an item. You just can't even.
So, of course, now I'm working on a list of qualities just for fun and amusement. That's not to say they won't end up in my campaign at some point.
Another one:
Item/Vehicle Quality: Inconsiderate [species or trait][Ranked] The design of the item, weapon, or vehicle makes it difficult for members of certain species, or species with a certain trait, (such as multiple or fewer limbs, smaller or larger silhouette, variant sensory ranges, etc.) to use. This design adds 1 Setback per rank to skill checks to use the item, pilot the vehicle, or fire the weapon.
"I don't think the Empire had Wookies in mind when they designed her, Chewie." -Han Solo
edit: Please share any that you come up with. Just for fun, of course.