1) Staging and imaging: My system setup already reproduced an excellent stereo image. However, with the HCPS in the system, the the depth, or "space" of the soundstage was improved; be it a super-close miked jazz performance, or the London Symphony.

2) Fine details, and instrument separation are better. There is no sense or anything being smeared, or constrained. Brushes on cymbals, as well as the fine, delicate harmonics from a single voice are more distinct. Leading edges of cello, double bass, and guitar notes have more detail. You can even hear an improvement using (decent) FM radio as the source. Impressive!

Note that in no way did the HCPS alter the tonal structure of the system. Resorting to a cliche', it "lifted another veil" from the system.