Nick, on a point of terminology, Yamaha refers to the feature that they've had for several years, adding artificial ambience, as "presence" speakers. The Dolby DPLIIz processing of material already naturally in the recording has been termed "height" since it extracts non-directional ambience material(rather than the left and right surround ambience which DPLII sends to side surrounds)which, when present, frequently comes from above.
Since this is non-directional material, wide dispersion speakers such as the QSs would appear to be ideal. Dolby has most frequently been suggesting this as an alternative for someone sitting almost up against the back wall without room for a "7.1 back" setup and instead assigning the unused back channels for a "7.1 height" system.
