In this hobby, yes, many differences are in the head. Pshyco-acoustics is a real topic. Don't get me wrong, there are differences between gear and cables, but to varying degrees. Some differences are obvious, some are very hard to detect, and some cannot be detected at all. Just like the size of the pea under the mattress, sometimes it is so small that it is undetectable.
On another note, remember, different is different, and not neccessarily better.
On another note, remember, different is different, and not neccessarily better.