Viper Lair posted a review on the Ultra X-Finity 500 Watt PSU

Performance was also pretty good. It produced slightly more stable voltages than the comparison Enermax power supply, especially in regards to the CPU voltage. Though as a note the voltage data was taken using a software program so it isn't the most accurate, though for a comparison between two power supplies in the same settings it works just fine. As for noise, well there wasn't really any to speak of, though the Ultra was somewhat quieter than the Enermax.

Ultra X-Finity 500 Watt PSU Review