Hi @grannyring : thank you for posting your impressions on Majestic MKII power cord.
I have no doubt the Hijiri sounds great, as @lalitk also attests. But a think a fairer comparison with your $1,500 HIJIRI Nagomi power cord would have been the graphene insulated Zavfino Silver Dart power cord at $930 MSRP, 10 gauge, especially for an amp, instead of the 12 gauge, $390 Zavfino Majestic.
The Silver Darts are top of Zavfino line, graphene dielectric and shield. I have two on my way.
The Prima PC I have (also 10AWG, no graphene), at $560 is an outstanding PC, competing right there with much more expensive power cords I have owned and still own.