This thread has gone quiet, so maybe I will report what I learned from talking to the sales folks of Aperion, ZVOX, and Polk. The Aperion guy was sure that their system was as good as Deftech mythos ssa, Polk Surroundbar, and Atlantic Tech FS 5000 without having heard them (he was up front about this, still an odd certainty). ZVOX guy seemed a bit defensive when I asked how a TV's 2 channel output could produce surround sound. Seems to be the point of high resolution, multi channel sound sources is to process and reproduce them faithfully. Polk seemed the most confident, pointing out that they were the first (true?) and that Deftech was a sister company. Finally, Crutchfield (don't have much specialty store options here) guy felt like saving on Polk vs. Deftech ($200-$300) and putting that into a good sub (I'm thinking Outlaw LFM-1 compact or Deftech supercube iii) would represent a better value for my small area.
So, I went with the Polk Surroundbar. No sub yet, want to see what it does without the sub and then add one.