I voted for both.

Squall's Revolver looks too heavy and cumbersome, although I love the engraving on the blade and the pendant dangling from the handle. Seifer's Hyperion, on the other hand, looks lighter and easier to use, and the blade looks razor-sharp. The design is plain, though. Both seem equally powerful.

So I guess Squall's wins for the design, while Seifer's wins for the usability, and they both score the same for power.