Bilbo,

You are correct. My polite phrase for what 7.1 adds is "a modest improvement" and, in many setups, not much. It rather depends on the room and the layout.

For larger rooms, the additional two speakers at the rear will certainly yield much better coverage. In average-size rooms, you may notice little or no difference if you are using QS8s as the main surrounds to each side.

And yes, the 7-channel stereo functions can be quite pleasant for filling the room.

Regards,

Alan Lofft,
Axiom Resident Expert (Retired)