I think I have an idea to improving the Gauntlet. This is the only way I think can make the Gauntlet more useful than it is.. even though it will never be the preferred relic of choice, this will increase its overall value for a longer period of time...
As part of equipping the Gauntlet, the bonuses from the compatible weapon should also be doubled (this includes Evasion and Magic Evasion).
This is significant for a number of reasons..
1) If there is a rare, one-of-a-kind weapon early game, this may be a tempting option to use.. especially when this relic is in limited supply in the first place.
2) It would nullify/equal the benefit for the Genji Glove provides for equipping two of the same weapon.
This alone won't make the Gauntlet better, so I also propose the following addition..
Not only will the Gauntlet double the attack power+bonuses, it will allow one to strike twice! This is fundamentally the reason why the Genji Glove is better.
Now it seems like the Gauntlet now would be better, but still, let's remember the following problems the Gauntlet normally has..
1) Limited supply - really, at most, you get 3 (1 @ Kefka's Tower, 1 @ Umaro's Cave, 1 @ Returner's Hideout). I don't recall any method of getting more.
2) The Genji Glove still allows to equip interesting weapon combos (Drainer+Atmaweapon, etc) that don't have to suck..
The only issue may be that the some weapons aren't 2-handed compatible.. but I've found that it only applies to Claws+Gambler weaponry (which is primarily a throwing action), which is a minimal subset of stuff to worry about...
If FF5 ever leached this idea (feel free to leech that idea), this would finally make 2-handed weaponry all the more useful.

I forgot to mention that the attack power shouldn't be doubled if the two hits idea is implemented...
The basic idea is that my proposed Gauntlet's new purpose is to essentially be the Genji Glove with a "virtual duplicate weapon" on the other hand.