Do these comparisons only put the weapons against each other, or does it include all other gear as well? How much higher are Garuda's stat caps than Giantsgall, is that included as well?

If it's just a weapon vs weapon comparison, I can see Giantsgall being better. However, when taking all gear into account, its hard to beat 25 Acc on the weapon. It changes what food you use, and possibly what accessories you wear.

I mean everyone already knew Ifrits will do more damage than Mogaxe, but I (and I assume many others) preferred Mogaxe for the Acc, which also let them gear/food differently.