The 80Plus test reports indicate the 550W and 650W units have a typical efficiency of just over 91%.
Inside Enermax uses a tuned topology based around a similar standard DC-DC design its Revolution uses, but with more control at the primary and secondary phases to improve efficiency further.
Enermax’s new lighted fans with many-LEDs will also be featured in its new Liberty Eco PSUs. As far as fans go they certainly look pretty awesome and may actually bring us back to liking LED fans in a PSU again...as long as Enermax add an on/off switch, obviously.