The chorus of experience!
I'm on the side of mix 'n match. Cobra on most components, but an older model, like originals Python and KCs on a digital front end can bring the best of both. Digital front ends need quieting down, and that compound they had makes the line they're now running (z-trons) sound even quieter. I'd say it also firms up the image focus, too.
This "neutrality" thing is aces, but sometimes "neutral" means "grey" or pearly-white. I don't know this is true, but some people will trade resolution for "weight." I saw a point TAS writer made, Jonthan Valin by name. Resolution and tone color didn't always go hand-in-hand. So, you can get neutral and lose warmth/richness or whatever you may. If the goal is neutral, what is music? Neutral? I don't think Boston's hall is neutral: it's really, really warm - sounding. So aren't we talking about the halls we hear music in as much as the components? I'd love to hear the Musikverein before I leave this planet - and the chances are good I will.
Anyway, I like the first line of the Shunyata power cords. Second line, eh. Third line, better. 4th line, great. Fifth line, great too, but measurement-oriented and we all know music don't follow measurements. The fifth line is real good, but it doesn't have focus like the first line, and less weight to the sound. Me, I'd stick with a mix or first Shunyatas , maybe on the conditioner and the digital pieces, and the rest Python and the others.