Two new 2.5m Silver Dart power cables arrived a few days ago. I first put them on the Kii Three active speakers and then I tried them on the headphone amp and standalone DAC. After the first night listening on headphones, my old cables were put on the used market. Those were excellent cables from a highly regarded manufacturer. With just a few hours on the cables, I asked my wife if she noticed anything different with the music. She listens to music on the Kiis and she said the music is more clear and something along the lines of less shouty. She also said the performer is more in the room. I agree with her assessment and then some. Again, this is comparing well broken in and well regarded cables against the Silver Darts.
As reported, these Silver Darts are stiff and that's one reason why I ordered 2.5m instead of 1.5m. That was a good decision for my application.
A few days after receiving the power cables, the Silver Dart XLR cables arrived. Unlike the power cables, these XLRs did not show their magic so easily the first night. It will take time for them to shine but I can sense the improvement already on night #2.
Like the OP, the power cables are connected to a Shunyata Everest power distributor powered by an Omega XC cable. My setup is designed with transparency as the goal.