@davidb928 - you have opened a can of worms with this thread, simply because different people have had different experiences with both formats and from that, they will share very differing opinions.
I have experienced some excellent cables and some very poor cables in both RCA and TOSLINK formats from some very reputable brands.
Both formats can be subject to errors in data transmission due to choices in materials and construction methods.
So it is not a case of Toslink being better or worse than RCA
When it comes to the RCA variety, selecting a cable with the a more advanced cable geometry will likely yield better results
Cable geometry is how the individual wires and wire gauges inside the actual cable is selected/designed/configured.
When it comes to TOSLINK, as a "general rule", you can avoid some of the pitfalls by selecting cable that uses glass as the optical medium. But there are also some good cables that do not use glass, so it is not the only criteria. It does not suffer from induced noise, but there are some have experienced issues with the optical/electrical conversion circuitry.
With either format, the digital interface in the respective components may have issues, after all you are converting digital bits to an analogue signal, so again, no matter what cable type you select - the problem may be in the components at either end of the cable.
My current choices...
- I use TOSLINK optical cables from DH Labs on my A/V system. They may not be the absolute best out there, but they are great value for money and do the job adequately
- On my 2 channel system I tend to be more discerning, so in the past I have used digital RCA cables from KLE Innovations on my 2-channel rig - a little more pricey than those you mention above, but well worth it.
I now use a Bluesound Node 2 for digital music, so there is no longer a need for digital cables. But the power and Interconnect cables have proven to be critical in achieving the best performance from it.
I hope you find your ideal cable
Regards Steve