Last night I swapped back to my OCC version of exact same interconnect cables, with the same design, length, same connectors as my OFC pair, made by the same Co. It becomes more of a comparison of the different metal used.
Its still a surprise to me after years of testing and validating this - how its possible to actually hear deeper into the sound stage, with more detail and separation of individual instruments with OCC vs. OFC. Its not always "better" in all cases.
There are times I also appreciate the different type of tone, texture, and mid-sound stage the OFC copper offers even with its noted granular flaws in the metallurgy strands. In my setup, the same OFC interconnects can offer a bit more of a vintage type of tone, which is fun too. I like both for different reasons. I still find myself swapping back and forth every once in a while between the two different types.