PS Audio AC Regenerators

I saw a feature on PBS Nova show (topic: In Search of the Perfect Battery). In the show, they went to a factory in California that makes giant flywheels for energy storage (maybe six foot diameter, 4000 pounds). 
You could put one of these in your basement for virgin electricity -think of the low noise-floor! The P.S. Audio approach is similar -take electric from the grid and transform into pure, virgin juice!
I tried one of their early units (circa Y2K) but didn't hear much improvement. Think my local A/C was pretty good to begin with.

@jonaiken - Did you try a staggered start-up with you ARC amps? Could be a full-system surge, at turn-on, was causing too big a load for the P20.
Did you try firing them up one-at-a-time?