PC Perspective checked out Ultra's X3 600W
A quote from the article:
Ultra Products X3 600W Modular Power Supply Review
The X3 600W modular power supply is another excellent addition to Ultra's X3 power supply line and should appeal to mainstream enthusiasts who don't need a 1kW PSU. The build quality appears to be excellent and the output voltages were all very stable and clean, even when delivering 600W at 40C. And modular FlexForce cables, a black-chrome finish, active PFC, and a lifetime warranty are nice to have also!
Ultra Products X3 600W Modular Power Supply Review