I need some input from you guys who know what this is:
Active PFC (Power Factor Correction) vs. Passive PFC.

I already understand that Active PFC is the better of the two methods, but I need to know more about it as I am still shopping for a new Power Supply.

What I'm really asking is if somebody could speak in layman's terms of the advantages of having a PSU that uses Active PFC.

Would there be any perceptible differences between PSUs that use each method? Or, is the Active PFC kind of one of those hidden benefits, where the better technology is being used but you're never really aware of it in practice, i.e., you wouldn't be able to tell if a given PSU uses active or passive without reading the tech specs.

Have u seen these?

http://www.endpcnoise.com/cgi-bin/e/pfc.html

http://www.seasonic.com/support/answer_pfc.htm

http://schockpower.com/pfc.htm