Are audiophile outlets overated or offer much if anything?

I recently had many of my wall outlets replaced  (so that a portable heater wouldn't be too much for the cheapies the builder put in) with low-grade hospital ones that couldn't have cost much more the $10 or so. They weighed twice as much & clearly had better parts. On a whim, I also had the outlet my audio was plugged into replaced as well. Fall on the floor difference in quality.  Clarity &  bass (that had much more impact) were immediately evident & harshness was not particularly accentuated either.  My speakers are Focal Diva Utopia Be's (1st generation) with good electronics.  They do double duty as either for TV or strictly audio use (I find putting a duvet over the screen helps acoustically for audio listening).  Even TV sound has huge gains in intelligibility/clarity (routed through my PVR with good audiophile cable).  To whatever degree a centre channel might've once been desirable - it isn't now.

How much more do the fancy audiophile outlets (Cardas/PS Audio & competitors etc) offer?