@ghdprentice when I installed my 5 lines in my listening space I did an experiment. Installed a Leviton 8300-R 20 Amp, Hospital Grade. Installed a standard HD .99 cent outlet, installed Monosaudio 20 Amp Audio outlet, installed Cardas 4181 and a Audioquest NRG Edison Duplex.
Zero difference after 90 days and swapping from outlet to outlet, amps and integrated Zip, Zero, Notta. so buy the .99 cent outlet works as well as the $200.00 one. Electricity has no sound, interference on your lines will have an impact but these outlets do nothing to filter noise.
BTW the Cardas and the Monosaudio look identical.
Electricians do recommend replacing receptacles as the get old, baggy (lose clamp force) and the plastics can crack. Copper or copper plated silver are your best conductors for outlets. Hospital grade often uses is rhodium
Is Rhodium more conductive than silver?
Rhodium is a precious metal from the platinum family. It is hard, acid-resistant, and has a very high melting point (1964°C). Compared to other platinum metals, it is a very good conductor, but still only half as good as gold and just one third as good as silver and only 50% of Copper.