Lots of claims and I bet zero evidence, especially the claims that can really be measured
Soundstage is an issue of phase shift both at recording time and by the speakers capability to reproduce them, not an isolation device of cones, total bs and voodoo.
CD player will NOT benefit either, zero. That has been measure and demonstratede by Ken Pohlmann, and published some time back.
No, outside of a turntable, it is not warranted.