My statements here are based on my own exp and point to those folks who aren't extremely well vested financially.
With respect to all others, my exp with wires which are best used through the whole of the system are as fine and well as that scenario indicates. Just as with components, one achieves a more certain step to overall synergy by going 'same same' all over. Sometimes.
I've noticed too that mixing components does change things, and can indeed improve upon system performance.
having tried some facets of that same same cabling, yet not 100% throughout, just with power cables primarily same brand diff models though on each piece... I find the main issue with going with the same brand all over just as daunting a task as is mixing things up, but the mixing seems to come out cheaper... and with substantially good results.
With MIT ICs on source and as mains, the sound I got then was far less colorful or vibrant. Not as harmonically rich as it had been.... somewhat bleached. I used Magnum 3 on source and Shotgun 1 as main.
With only one MIT in place things were far, far better, richer, more natural and less washed out. In conjunction with tube + SS amp, and all tubes.
I've not tried the MIT Oracle line at all so it may well be different, but I found it/them, cost prohibitive for me to try.
Similar results but different, came by way of using Nirvana ICs in those same places, but again, neither IC was the same model... SX on source, and SL on main. the result was a lackluster performance.
Nice. Way more than easily listenable, but uninvolving.
however, using Nirvana SX + MIT Magnum was a great exp. Same thing as using SX on source and HT Magic II as mains.
Prior to those experiments I used SR ICs and SR + MIT ICs for some time. SR + MIT were more than satisfying IMO. Yet SR + SR was not. I lost bass and midrange info the MIT Magnum supplied in spades.
So for whatever reason, my exp keeps showing me some combination throughout does lead to higher levels of performance.
Again, Ill not dismiss the statements of those who validate the use of a single brand either. All Im saying is there is more than one way to get to greater levels of involving, and satisfying, sonic recreation.
With power cords, I've found both ends of a rig can be improved by stepping up there. Front and back. Source and amp (s). Initially. Later or certainly thereafter, the preamp needs looking at.... some.
The bigger bang for the buck does seem to come by addressing each end of the chain first however.
RWV depending on both which brand and which model within that line up, you pick. So one needs to try out a few brands, and/or models of same same or mixed to see what's best. I can only say that there is indeed something to the idea of replacing OEM power cables.
As for the non migratory power cords being best suited to that particular piece.... how do you know? Add an adapter and plug in another upscale power cord.... you will realize a difference IF your gear is sufficiently resolving.
Don't think so? Spend the $10-$15 for the adapter and find out for yourself.
BTW, also for those folks... are you using a power line filter or conditioner? Which pc is atached to it? Then switch out that pc with some other and you'll see a different influence therre as well. The supply cord is way important and influences everything downstream of it.
You can think of pcs as filters. Like a gas line filter that keeps trash out of the carb or injectors. Same thing. Actual dedicated filters and conditioners do it better of course.
Or you can think of it like changing out the coil and spark plug wires to a higher level of performance units. you will indeed gain better energy/spark at the plug/component and realize more power or again, performance.
If you do not try it for yourself, it's all pie in the sky anyhow.