I still have strings that I brought home with other stuff when I came back from US - I take a set and put it on a Guild - and WOW - I Feel Good - dadadada - so good, so good . . . - naturally I do not have a reference.
Years ago I worked with a trio - the guitar player was the dictator - but he had this idea, that whenever he goeas on-stage, the strings must be new, because the audience deserves it - one day we had two outdoor gigs about 100 miles apart and tight schedule - in the van heading to second gig he was putting new strings on his Telecaster.
I could not hear any difference - might be fatigue within a hour of gig - but I still respect him for that - even though for other reasons he does not deserve that much of my respect. . . . . . .