OK, here's one:
JohnK always touts listening to two-channel music in multi-channel surround as your receiver will extract all the natural ambiance cues and direct them to the appropriate place in the (now surrounding) soundfield. I can understand this with orchestral and classical selections, which (almost solely) enjoys.
But what about Rock and pop recordings? There IS no natural ambiance as the instruments are close miked, recorded on different tracks (to be adjusted by panning after) or recorded on separate days.
The receiver might extract info that it sends to the surrounds, but is there really anything natural or correct about it in terms of simulating a live performance?
::::::: “Yum. I'd love to gnaw on those with my ears." :::::::