Mitch2
Art Dudley wrote a pretty good (accurate) review of the SX Ltd. some time back in Stereophile, comparing and contrasting them to Nordost's Valhalla.
Bruce Richardson of Voodoo cables makes an Ultralinear cable comprised of both copper & silver and it was also on the top end of my short list prior to me settling on the Res Ref x2... back then. Since however, the SR Acoustic Ref active in their tesla series does edge out the Res ref near entirely save for the bass impact and more weighty feel the RR's provide. The SR AR do offer a tad more resolution and near the bass of the RES REFs... and come across very naturally. Some say more analog like, but on that point I'd have to pass as I've no analog gear.
The SX's lay somewhere in between the SR AR & SR RR but are more naturall than either of the SR wires. With a high res system, the SX + either AR or RR will indeed satisfy... duller systems might not respond as well... for ex. SET like sounding gear whose fingerprint is way lush, perhaps... and that's just speculation on my part given the way they handle sonics.
With the SX in there somewhere (it's usual place is on a source but I've found it works well as a main too), re-creation of the original venue is clearly evident, as well as is a more organic presentation.
One last note on the SX Ltd. is they reject EMI & RF well indeed for SE cables and act more like XLRs in that respect. they're quite clean sounding and without air flowing radiations or artifacts... and I'm using my SX as a main IC.