Stein Harmonizer's

The other night a dear friend and major audiophile brought by three (3) Stein Harmonizer's. We were simply stunned by how much they improved my system (Devialet 220/Harbeth 30.2's/Nordorst, Red Dawn speaker cables/Torus TOT AVR). The soundstage, clarity, dimensionality etc. were greatly enhanced.  Has anyone experienced anything similar? I was utterly incredulous until I heard the difference/improvement.