There are exceptions I agree. The stock is not great as copper cables go. It is of course more bottom tilted than say silver or SPC cables. From my experience run of the mill OCC copper will keep all the positives of stock and more at the bottom, with a cleaner background and slightly better instrument separation and resolution. Don't want to overblow the differences. It's what you'd normally expect from a cable swap.
Sounds about what I heard when I swapped stock Audeze to the Q. All subtle but improved.