OP
I ran a years long test using a bunch of high end receptacles, and came out with a few winners:
Furutech GTX-D(G gold) or GTX-D(R rhodium) depending on your tastes, Oyaide R-1 which has platinum and palladium coating)......these stood out amongst all others I tried. I am installing one each of these on 3 dedicated lines in my new listening room
If anyone is on a budget, the Acme Audio Labs at $60 are excellent....and great replacements for stock receptacles without breading the bank. Silver plated over higher copper content brass