Although this thread is 4 months old, since you asked, and given a few (minor) pieces of our equipment are by the same manufacturer, I decided to hazard a response.
My electronics are CJ (preamp) and ASL Hurricanes amps. Interconnect is Nordost Frey 2 and Tyr 2, and Nola speakers. Finite Elemente stand with Cerapucs (had Cerabases at one time) and Stillpoints under everything (except the speakers. Still thinking that over, since they're on a thick wool carpet on a wood floor that is good, but not wood over concrete). I have a PS Audio Power Plant P300 (had the PPP: sold it), and had Audience, the 6T (sold it). Arcam CD players, VPI Classic and Dynavector cartridges (2 of them on 2 different 'tables).
So, to respond to your original question, it isn't likely that the Sigma HC would be overkill. I have the Alpha HC, after talking to Richard at Shunyata, who had to convince me to not use the Sigma analog for the PS Audio. I had NO intention of spending a small fortune on power cords, and I've had the top Shunyatas since Day 2, along with an extended - and simultaneous - run with Valhalla (interconnects, speaker cable, power cords) for a few years from 2003-2006. I still have two lines of cords, Nordost and Shunyata. Nordost is great, but I wish their pricing wasn't stupid expensive (and I don't care that there are other cables that cost even more: they are also 'stupid expensive').
Now, the Sigma's breaking in - and it had a 10 head start on the Alpha. Anyway, the Alpha HC, a newborn, at 4 days old is also breaking in, but there was that window of time (the first 24 hours) where the all Shunyata hint at the proverbial love-affair-to-be-remembered. And I'm using an NAD integrated at the moment, since I don't have to worry about blowing a resistor when breaking in equipment. The older Hurricanes would do that, as I'm sure many members would remember. The Alpha HC, in its first 24 hours and placed on only one component, the PS Audio, ran all over the Sigma. Unexpected? Definitely. Keep in mind, I said 24 hours.
So, the Alpha HC shows itself to be 'of a piece', meaning it is sonically continuous from the top to the bottom - and it showed this somewhere between the 12 - 18 hour mark. Unfortunately, I had to leave that party and go to one populated with humans. I will say that when I returned 10 hours later, it had left the 'love affair to remember' stage and morphed into its schizophrenic, 'Fatal Attraction' stage, and after listening for 10 minutes (or less!), I departed. I knew what to expect (I mean, I've had Shunyatas before and I've heard them change before), but still, I didn't expect such a change from a highly dimensional presentation into a flat one, like seeing the world thru two eyes, and then suddenly, you close both eyes, open them again and discover you have turned into the one-eyed Cyclops, sitting there wondering 'where'd the depth go??' I await its return after it has had sufficient lithium injections and turns into Deborah Kerr again. The Sigma and the Alpha HC do this 'good seed, bad seed' thing more obviously than any previous generation of Shunyata power cords in my experience. And the demarcation line between good and awful is as stark as drawing a line in the sand.
So, the Sigma, which arrived ahead of the Alpha by a week or so, was great on the PS Audio, but when the Alpha muscled its way onto the PS Audio, it demonstrated that, even at less than 24 hours, despite my having initially (only in my head) regarded it as the one likely to be the 'First Runner-Up' in the Miss Universe pageant, it was not. In this one application, it was the actual Miss Universe (Miss Philippines) and the Sigma was suddenly dethroned, as was poor Miss Colombia in last year's Miss Universe pageant. The dynamics were electrifying by the 10th hours, right up to the 24 hour mark, (where it turned into Glenn Close. 'Course, I'd left that party too soon, so maybe it turned evil at 23 1/2 hours), but never mind that. The NAD was suddenly testifying like it had morphed from the proverbial 98 pound weakling into Charles Atlas (and if you're too young to remember the analogy, well...it was BYT (Before Your Time)! An interesting thing, though, was the that the PS Audio got very, VERY warm. Despite its reputation for being hot to the touch, it had never been hot to my touch - and I'd had three P-300s in my time: usually it was barely warm, in fact. Don't know why that happened, but aside from that, the sonics were riveting. I suspect that the high current of the Alpha was akin to releasing the PS Audio from its 'holding pen,' like letting a Brahama bull out of its chute at a rodeo. The NAD has astounding dynamics, given its modest provenance, but with the Alpha HC, (and the NAD is plugged in to the PS Audio), it's doing leaps, jump, and double backflip twists like it's Simone Biles. It was never like that before.
Now, a word about the Furutech: Ive had Furutech fuses AND the GTX-D Rhodium, as well as the IECs, which I put into the Hurricanes years ago. The character of the Hurricanes changed, and most specifically: the midbass. And nobody messes with my midbass. If your component messes up the midbass, it is gone. And the Furutech definitely bleached out the midbass, as I discovered after I got the GTX NCF outlet. I'd have normally noticed this 3 years ago, but tragedy was happening and I wasn't focused. And I'm still going to try Synergistic's outlet, because I like to experiment, although the NCF is anything but bleached. Disturbing that that escaped, but like I said.... But unless that's a newer generation of Furutech power cords, you may be listening to a 'pastel' palette, although you may not hear it as such.
I'd at least get an Alpha HC and try it out. I'm sure the Sigma is better, of course, but it's a lot of money. Although, you HAVE spent a lot on your system, and if it were me, I wouldn't want to find out years later that one component was preventing the system from demonstrating its full glory. I'll update again after the 'Glenn Close phase' leaves...
So, that should answer your question about having BOTH cords simultaneously, and testing them, one right after the other, on the same unit, which will give you an idea of how your PS Audio will likely get a testosterone injection should you insert even an Alpha HC on it. Believe me, I scoffed at the idea that the HC was 'all that'. My bad. It IS 'all that.'
