Aaron- And modes like CES by Outlaw and xS by Rotel are *designed* to spread the 2 surround channels of DD or DTS (or even DD 2.0/DPL/2 channel stereo however encoded) through up to 4 (surround/rear) channels. Most receivers (now) do have equivalent modes.
HC- I suppose it would depend on how good the original mastering was. I think that in an *ideal* world, a disc specifically mastered to DD EX/DTS-ES "standards", *should* sound better than using a generic matrix expansion mode on a 6.1/7.1 system. But of course, ymmv... :)
Joseph- Keith is correct. But I'll add a little more. Logic 7 will also fill the rear speaker(s). And modes like CES for Outlaw's new pre/pro, and xS for Rotel's new one.
But, I do believe that HK's implementation of Logic 7 can only be used with 2 channel sources. I think there was a big...