As always, a lot depends upon you, the listener, your system and your relationship to the music.
You describe the difference between using a clock and not as “subtle” where I didn’t even find the Rossini worthy of purchase without the Rossini Clock.
Without the clock the Rossini sounds OK but it requires the clock to give you the sense of space I feel is vital - to hear the micro-reverberations that tell you if an instrument was recorded in an acoustically dead studio, a concert hall, or in a studio with reverb added to give it the sound of a concert hall.
Likewise the sound of clock cables. If you’re not sensitive to the differences, that’s great, you can go with the most inexpensive functional cable you can find.
When I was auditioning cables to move up from the Cardas Clear I had been using, the difference between them and AudioQuest Wild cables was minimal enough to not be worth it.
But the AudioQuest Wel Signature? Oh boy.
There was just more “there” there. A more defined sense of where the performer was, or the space in which they were recorded.
This means nothing on a pop recording but everything on say one of the Sinatra albums where he is recording live in a studio with the orchestra behind him, or in an orchestra recording where you can sense the size of the concert hall. To me it made the difference between being able to pick out the violin is being over there and being able to pick out it was “two chairs in” from the front.
Now, is this important to you, even if it is easily resolvable in your system? That’s a judgment call, and certainly in some systems a power cord will make more of an audible difference, especially based upon what you are using now. If you’re running a stock cord, it may be a huge difference, if you already have a good cable it again may be minor to minuscule.