SURROUNDSFX  Astound Stereo works exactly as advertised on my Studio machine, alongside an RME FF800, Logic Pro, WaveEditor, SoundFlower etc, monitoring through BlueSky System One monitors. I use it for production work, inserted into Logic via an aggregate device with SoundFlower + FF800.....with moderate settings it does a good job on submixes/stems. I would have expected lots of hiccups, to be honest, as most software like this tends to interfere with my peripherals/workflow etc too much, and thus usually never makes it past a short evaluation period before it is uninstalled... but i was pleasantly surprised when i installed this. There was one bug in V1.1 (no sound audible under certain circumstances...that's what the "4" on "stability" is for ;-) ) which got addressed within a week of my reporting it to GenAudio...Nice! No issues with the later software versions. How does it sound? On recordings containing "real space" information, such as orchestras or jazz....it's quite stunning. You can increase the amount of "envelopment" with a fader. No phasing artifacts, just "bigger" and more detailed, without sounding over-hyped. On stuff using synthetic reverbs and panning for creating a sense of spaciousness, the effect is slightly more subtle (or sometimes, interestingly, way more dramatic....), but you still get a noticeable increase in "niceness".

Definitely a useful utility.  
(Version 2.1)