I find it hard to believe that so many could find a massive enough tonal difference b/w the QS4s and 8s to make it worth consideration.
Those who've heard the M50s and 60s have often declared the difference as subtle and those 2 speakers are far more different.
QS4s vs QS8s should come down to room size more than 'tone' differences when deciding. Larger speaker for larger rooms.
Incidentally, i do believe the QSx series will match well as surrounds with Monitor Audio mains. They've been setup with some Tannoy Saturns in a friend's HT and they work excellent. Tonal differences for surrounds is over exaggerated too often IMO.
