Think you hit the nail on the head when you said it's like swimming in music, very apt description. Haven't moved my Holostages around as I am just enjoying things as they are.
I strugggled to come up with an appropriate description & swimming seemed best at the time. One skeptic on another forum suggested I just listen to my surround, which is only used for A/V & not 2ch stereo playback.
But even the notion of swimming in music doesn't quite capture what's going on here. It's much more than that. More like being submerged in neutral buoyancy, because what your hearing has way more body, saturation, decay that goes on forever & silent background when the last note in the decay finally disappears. Think slightly more reverb & impossibly long decays.
Performers & instruments are no longer just layers, but instead, they appear in 3D cylindrical fashion which stimulates your brain to visualize each performer & instrument in 360. Remember, the Holos have already portrayed the listening experience in 360 degrees.
The visual allows you to have a much more realistic feel for the acoustics of the room in which the recording was made & that same visual helps to portray the music in a more coherent way.
Experimenting with placement is critical to the desired outcome, but it's very easy to do, since the boxes are only 3"x3" & passive by design. No cords necessary. In fact, I'm prepared to eat crow when I say Holostages significantly outperform several other very pricey, but highly effective room treatments!
Finally, some very bright scientific minds developed Holostages, so it should come as no surprise they are so effective.
More later!