I own two GPX-R (white plugs; for power distributor and integrated amp) and I am waiting for a third one for my digital source (instead of the GPX, red plugs).
GPX is a very dynamic cable with a strong mid-bass but it hides some microdetails in the higher frequencies, resulting a "dark", "warm" sound.
Recommended for systems weak in the bass and/or too bright/harsh on the top.
GPX-R shows even better dynamics, great bass strenght and definition, real neutrality with very good details, focus and soundstage, an almost universal cable, recommended for all systems.
GPX is a very dynamic cable with a strong mid-bass but it hides some microdetails in the higher frequencies, resulting a "dark", "warm" sound.
Recommended for systems weak in the bass and/or too bright/harsh on the top.
GPX-R shows even better dynamics, great bass strenght and definition, real neutrality with very good details, focus and soundstage, an almost universal cable, recommended for all systems.