It's better than Gaels in my opinion. It saves you leveling strength and dex in exchange for just leveling intelligence, it can trade ultra weapons with its weapon art and come out on top. It goes through shields somewhat.
Gaels greatsword weapon art combos, yes, but is pretty easy to evade and doesn't have the poise frames.
I think people put Gaels on top because of the stab R2, which is ridiculous, and too many low level poiseless sorcerers use this weapon