At the very top you just get different, not better. Witness some of the greats noted hear. So no single example, but at the last AES in NYC, ATC had a side room set up for auditioning their speakers. I wandered in during the silence prior to them cueing up Joni Mitchell's "Both Sides Now" from the CD/DVD Audio set of the same name recorded at Air by Allen Sides in 2000.
Truly stunning. Especially in the way that the subtle details of the vocal contributes to the emotion of this song. I saw several tears. Seldom has a room at AES been so quiet after that tune ended.
P.S. I bought the set later and in general was disappointed with the rest.