Hi Bob, Just to re-clarify my position, I don't prefer to "collapse the surround to the back of the room". In fact, if you re-read the passage from my post that you quoted, you'll notice that I advocate the use of CES to specifically keep the surrounds from collapsing to the rear (which happens with EX/ES decoding only when the surround channels are mono or contain mostly mono info). Besides, collapse to the rear is not the same wanting surround-back content (and only that content) to emanate appropriately from behind the listener and not from anywhere else. Though you are correct about proper 5.1 systems, keep in mind that the original poster asked about 6.1/7.1 systems, where some sounds will necessarily have to be localized behind the listener. The differences lie in how each processing technology handles rear vs side surround imaging.

BTW, while di-pole speakers themselves might create a "cloud" of sound, it doesn't mean that the overall effect will be "non-directional". Even on a system using di-pole surrounds, listeners will be able to tell surround content coming from their left side vs sounds coming from their right side. This is similar to my experiences in EX/ES equipped commercial movie theatres: while I couldn't locate individual speakers (especially in the dark), I could readily tell if a certain sounds was coming from my left or my right or behind me. A diffuse surround field may lack in clarity, but that doesn't have to mean non-directional.

Best,
Sanjay