The Corsair RM1200x SHIFT wins in 5 out of 9 comparable specs, with 3 ties. Its biggest advantage is PCIe Connectors (350% better).
Focus GX-650 wins in 1 spec (MSRP: 65% better).
Recommendation
Choose RM1200x SHIFT if you want the best overall performance — especially pcie connectors.
Choose Focus GX-650 if msrp matters more to you.
