Above a quality threshold for materials and deisgn/layup, improvements or just lateral moves, i.e., differences are miniscule even in the most resolving rooms + rigs even to a well trained listener. There is no such thing as "night and day".
Spotting differences between a 200 dollar cable i have (a very special one from a home grown Chinese brand) and a 5000 dollar cable that was gifted to me is like pulling teeth. I have passed a blind test sufficient times for statistical significance. But, most of you will not, guaranteed.
