I don't find what Maxgain is saying hard to believe; it is essentially the same experience as mine. The difference between a stock and properly cryoed Hubbell (mine were treated by Alan Kafton at Audioexcellence/World Power) is the difference between night and day. I have said this before and will say it again: testing/listening to receptacles is problematic in the least because, to get a real idea of what the receptacle is doing, you should replace EVERY receptacle in your system, including line conditioner units, to hear the real character of the receptacle. Plugging a Monster conditioner into an upgraded outlet at the wall and then plugging the majority of your components into the cheap outlets in the Monster (or other line conditioner) is going to give you an idea, but only a small idea of what the upgraded receptacle is doing. It is not easy, but I have replaced 3 receptacles at a time each time I've compared different units. Personally, I could never justify buying the PS Audio, as it is simply a Hubbell 8300 (which I have used and is available for around $20, or $15 for an 8200-which is the same except for not accepting a 20 amp plug) with extra nickel plating, and there are many who feel that the nickel plating, or more of it, would be detrimental, not positive to sound quality.
In any event, when replacing 3 receptacles at a time, there was no problem in identifying fairly large sonic differences between, for example, the Pass and Seymour 5262's, the Arrow Hart 8200 and the Hubbell 8200/8300's. There were pretty substantial differences. There was a "quantum leap" difference moving from the stock Hubbell 8200/8300's to the cryoed World Power Hubbell 5362's that I am currently using, and, yes, I would describe it as being the equivalent of a component upgrade. In fact, I have done component upgrades in my modest system which have not resulted in the positive impact that replacing receptacles has had.
There is no doubt in my mind that ANYONE could hear it and would agree with me, particularly if they have a system that draws from 2 or 3 receptacles and replace them all at once. The phrase "blown away" gets thrown around too much in these forums, but in this case it applies. For under $200 for an average system, you will be "blown away" by what that $200 can do.