So I choosed one (believing it was better than the other). Only to find out later I switched off this effect globally. So I couldn't have heard any change, but only because of my mindset there should be a difference (from which I had to choose) I heard a very subtle difference and I actually choosed... (embarrassing experience)
Happens to me all the time. Thinking I'm hearing something because I'm expecting it. Clients are worse though!
I had one client sending me first and second pressing of a cd. She didn't like the second pressing, and wanted me to do adjustments (eq/balance etc). I checked the two cd's....bit identical. What she was reacting to was the slightly different design/color of the second pressing. Funnily, she preferred the cover of the second pressing but the "sound" of the first.
I don't trust anecdotes, including my own, in these matters. Humans and their emotions are involved. Hail science!