I stand corrected sdrani. I also don't think there is a right or wrong answer to this poll. High end Audio and HT Video is all about experimenting, and tweaking. One person's 5.1 nirvana is another's 22.2. I prefer the 2 sub setup. So IMHO 5.2 and and 7.2 is plenty of discrete steering logic to achieve a totally realistic soundspace as long as the low speaker array is duplicated up high. I do not subscribe to adding additional and complex 5.2 or 7.2 steering logic circuitry to create 100% discrete 9.2, 11.2, 12.2 or 14.2 sound patterns. Only the main (low) array need this IMHO. Careful attention to the High speaker placements will naturally add the proper space, ambiance, depth and delays based on calibrated output from the original 5.2 or 7.2 signals.
The natural, up high delays will lock in images and signals unlike anything one has ever experienced before without adding any additional steering logic artifacts. As I stated earlier, my dual, high/low 7.2 setup (14.2 speakers) literally melt the walls, ceiling, and floors away in the listening room. Sound images emerge in the room eerily consistent with where they belong on the screen. And sometimes, planes, spaceships, rockets, trains, cars actually seem to move beyond or emerge from boundaries past the walls. If a scene in a movie occurs whereby a person is yelling in an apartment below, beside or above the one depicted on screen; the sound literally appears to emerge from below the floor, beyond the wall or through the ceiling. It is completely lifelike. As someone suggested, the high speakers do not have to be big. But they should be rugged. By that I mean, capable of handling high power and current to approximate the low speakers. The mic calibration should be done on the low speakers to achieve the accurate and natural High speaker delays.