I currently use 2 Oyaide Tunami power cords DIY terminated with 004 plugs/IEC connectors on my mono block amps and they sound great. At the roughly $250 cost per cord I have in them, they are unbeatable!
They didn't sound great at first though....the break-in time is substantial for these products, but well worth the wait.
If you are lucky, you can buy used Oyaide on Audiogon once in a while at at decent discount.
The only downside is that there are numerous fake Oyaide plugs/IECs out there, mostly on EBAY.
It is fairly easy to know which are authentic or not:
No Hologram - likely FAKE (I think this recent feature),
No UL indication on end of plug - FAKE,
Big discount for new product - probably FAKE,
Round head screws to hold the barrel of the connector to the plug/IEC where the wires attach - FAKE, authentic Oyaide plugs/IEC use cylindrical head screws
I am happy to report that I got one seller kicked off of EBAY for selling fakes.......of course, he probably opened shop again under another user name.
Tim