Anyone have any experience with the Tunami GPX-R ?

I am using two GPXs and am very satisfied with the results. The first runs from an R-1 outlet to an Acoustic Revive distribution block and the second continues to my integrated. What little line noise I had is gone and both ends of the spectrum really opened up. Taste tests showed that installing the first GPX, before the distribution block, made the most dramatic difference in the system. The GPX's drawback, as Ckorody mentioned, is that you need a lot of real estate to maneuver the cord behind equipment, so I'm considering trying Oyaide's PA-23ZX for my CDP. As much as I like those bright red plugs, maybe this cable is more in line with the real world power requirements of a CDP (or ten CDPs!). Has anyone tried one?

Yes.. purely aesthetics.. I got it at Take Five Audio in Canada.. While Christ VH sent some techflkex free with the plugs and cable i bought from VH Audio I wanted the softer Nylon Material I found at take Five. It was difficult to work onto the cable till i tried some powder on the cable and got it to slide without streching.. I haven't used heat scrink on the ends..not sure weather I'll eventually do it but I don't move this cord often so I will probably leave it as is.

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.

The difference you mention between GPX and GPX-R is interesting. It is the same exact cable. The only difference is the connectors.