I used it once, found out what it did, and thought I'd never use it again.

But awhile back I was messing around in one of my saves and ended up turning Cloud into and an ubermage, giving him materia combos like (Sneak Attack)-(Ultima), (Final Attack)-(Pheonix), (Quad. Magic)-(Master Summon), as well as the Mega All, E-Skill, and the Master Magic materia, with the Circlet as his accessory.

The other two characters each had mastered Counter Attack and Cover materias, E-Skill, and the Tough Ring.

This wasn't by any means a "catch-all" party setup, but it was pretty fun to play around with.