The big difference I noticed is that the sound seemed more "spacious", ie it really sounded like I was listening in a much bigger room.

When I switched from the QS8s to direct-radiating surrounds (M2s) for a test it was like the whole room suddenly got smaller. It was really creepy, particularly since I have a bit of a problem with small spaces ;\)

I went back to QS8s and stayed there.

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8