Monstrous power cables

To satisfy your curiosity, purchase a Waudio cable on Amazon for about $50 and swap it in and see what happens.  It won't tell you if the $1,000 power cable is better than a $500 cable, but it should tell you if it's better to your ears than a truly budget cable.  The reason that I suggest the Waudio cable is that I have three in my system and noticed a significant difference with it for my amplifier.

I think there's an element of the size and weight that gives the impression of quality.  Maybe it's an integral part of the design and maybe it's done for esoteric reasons.  Every product has a marketing influence in the design.

I've actually stopped even trying doing A/B comparisons and instead rely on my reaction to the music over time. My system is also not at the same level as many on this forum and I'm not a quest to continually be unhappy and wanting something more.

Everyone has a limited ability to remember exactly how something sounded.

I've read that cables always require time to settle/burn-in to sound their best so a quick comparison isn't possible.

With the level of "everything matters" that people experience on this forum doing an A/B comparison is virtually impossible.  Even with parallel setups using the same equipment, do we really believe that they are truly identical?  Are they plugged into the exact same plug?  They are using different inputs with slightly different signal paths.  The sources are not in exactly the same location, so their relative positions to acoustic fairy dust is different.

Then there's the fact that different doesn't always mean better or work, sometimes its just personal preference.

If you've ever seen an interview with Jason from Schiit Audio, you may be familiar with his comment that after a couple of beers it's really hard to tell a difference.

Some of what I'm saying is intended with humor, but if you take everything you read on this forum it's not that far off from what should be expected.

Your son's presence could have literally changed the acoustics in your room resulting in a change in preference for you.

I think anyone willing to be open to confirmation bias and placebo effect will come to a point where it's impossible to truly know which is better.  My standard is if I have to repeatedly A/B to form an opinion it must not matter that much.

For a fairly recent A/B experience, I have a Maverick Audio TubeMagic D2 DAC that has parallel solid state and tube buffer outputs.  I had listened to both regularly and formed a strong enough preference for the solid state output that I didn't even both having interconnects hooked up to the tube buffer output.  In the process of upgrading, I purchased a Schiit Modi Multibit DAC and found it quite enjoyable.  After several weeks of listening I had the idea to compare it to the tube buffer output on my MA DAC and oddly enough found them indistinguishable to my ear.  I can only attribute temporary preference for the Schiit Modi Multibit DAC to confirmation bias/placebo.  I also have a Pioneer Elite SACD player that was indistinguishable from the solid state output on my MA DAC.  I found some information on upgrading the MA DAC, so upgraded the tube (Western Electric 396A) and three op amps (Sparkos Labs) and now strongly prefer the tube buffer output and find it far superior to my SACD player.  Now that I have an upgraded interconnect on my DAC I don't even bother using the SACD player anymore as it's simply disappointing in a way that makes any A/B comparison a waste of time.

If time and money were no object, I have have two identical pieces of everything so that I could always compare A/B with only a single piece of gear changing.  I'd confirm that I couldn't tell any difference with the dual setup and then swap a single item and compare and see if I could distinguish a difference.  It would be fun, but totally impractical.

I read on a forum somewhere a great quote that if an audiophile can see a difference they will hear a difference and I think there's some truth to that though I don't discount that with enough time and effort some people will be able to distinguish things that are far more subtle than most of us can.