Recently I went from the top Morrow Audio cable for the interconnection between Amp/Streamer to using Cardas Beyond Clear. Here’s another transparent vote for that line. Everyone touts their stuff so there’s that too.
Power cord(s) into Amp(s) can and do color too and there are lots of great cords to be had. I also had a great experience with ZenWave and use one into Amp. My wife and I picked the same one. How you like ‘dem apples?
Cords into PSU’s should be very good but the AMP and what you listen (TT, phono pre, Pre Amp, streamer) to deserve the best. A interconnect or power cord change may/may not matter but your big dogs deserve finery. One way to find out. Sure the rest of the cord gang matters but some matter more than others. Does a sub need a 4K power cord?
But you know all of this.
15k buys a lot of room treatment(s). If you’re happy but hankering for more, have you been there?