Are manufacturer AC cables good enough?

Mr. Denny has never done a double blind test publicly. Never. He refuses .. or makes excuses. Take your pick. But has never done double blind with any verification or validation. 

turnbowm, heaudio,
Please list the aftermarket power cords you have compared to stock power cords? 

There is abundant evidence that "expensive power cables" can make a difference - a virtual mountain of it! There are countless testimonials...

Maybe "reports" rather than "evidence" so everybody is happy.

"Please list the aftermarket power cords you have compared to stock power cords?"

I have compared a few stock power cords that came with different pieces of equipment. Some thinner, some thicker. I report that I could not discern any difference in sound.

If power cords matter in terms of sound, are all the stock ones clones that sound equally good (or bad, if you are a proponent of more expensive products)?

Instead of advertising expensive power cords, why not compare stock ones and report how they sound? It may be helpful to those on the budget.

"...with great success.    ie: https://www.synergisticresearch.com/best-of-show-awards-2015-all-major-shows/"

“Best of Show” Awards 2015 @ All Major Shows

Next show we attend is RMAF 2015 in Denver, October 2-4, 2015,

Did they win "Best of show" award at RMAF 2015, too?