I have that FX-600 great PSU BTW! Its currently running my opty 165 @ 2.6 with 2 XFX 7800gt's, 4 HDD's, 2x cd-roms, and 5xfans. Thing runs very cool and quiet with the system OC'ed. One Note though, the blue leds on the fan for PSU doesn't work, but its a great PSU.
Voltages are really solid, maybe a little flux now and then ( only because of constant brown outs!)
For running 2 7800gt's in SLI that require 28-32amp rail this PSU is under rated. I think they got their info mixed up.
If there is any more info I could give you RichPLS let me know I break the case open for ya!