Unless you are using $10,000 amplifier and a very high-end pre-amp, or perhaps a 300B single set-up, you are not really going to notice any real improvement over the RSC Prime.
I have used these for year with excellent results, on both older McIntosh, single ended tube amplifiers, and the Prism for most video sources and have had great experience.
I think there is a psychological expectation, which influences ones judgement in the very expensive interconnects, same with speaker wire.
I do however, prefer the Tara Labs cable to the older Audioquest, Ruby and Quartz, and I think this has to do with the difference in construction; I do not know about the new Audioquest cables.
MIT has made some impressive cables; I mainly use them in balanced set-ups, thus a comparison is moot.
I would stick with the Prime; after all these years past, I have never noted any degradation with these and see no logical reason to replace them.