More a showpiece than anything else. Most COR75's have Joyeuse (look up argument that TP gain is slower if you offhand ANYTHING with joyeuse on /nin) and should probably be used by itself, even if on COR/NIN.
Situational, it could be nice. I'd use it as a townpiece, of course, on /nin. Or when pulling in merit party you probably don't have much time to melee although Fire/Earth staff would give it a run for it's money. I'd probably go with this sword for the extra accuracy and fun.
If you want the perfect sword collection for COR75 I'd go for Joyeuse, Phantom Fleuret and Corsair's Scimtar
