That entirely depends on which characters you play it on and what you're looking for in a weapon. If you want a weapon that boosts a character's HP percentage and energy recharge to an insane degree, then yes, Jadefall's Splendor is going to be one of, if not the best, catalyst weapons you can use. However, if you're looking to build a main DPS catalyst character like the Wanderer, you're going to be better off using a catalyst like Lost Prayer to the Sacred Winds, which will increase your CRIT rate and elemental damage. So in order to consider Jadefall's Splendor as the best catalyst, you'll need to find the right situation.