The Corsair RM1200x SHIFT wins in 3 out of 9 comparable specs, with 4 ties. Its biggest advantage is SATA Connectors (33% better).
C1500 Platinum wins in 2 specs (Wattage: 25% better).
Recommendation
Choose RM1200x SHIFT if you want the best overall performance — especially sata connectors.
Choose C1500 Platinum if wattage matters more to you.
