It's not a great weapon in and of itself, but it's the only way in the game for Steiner to learn Armour Break. It's also used in synthesizing Grand Armour.
The last boss on the first disk hold one as a rare steal item, but otherwise you can buy them from Treno or Esto Gaza.
It's weird when you don't know a single thing someone is saying about a game!
I know Armor Break from X, but Grand Armor sounds nice, thanks for the advice, and yeah, I'll be doing periodic updates on this thread to show my development and so on.