True or False?

Regarding manufacturers and aftermarket power cords, last year PS Audio started recommending Audioquest for use with their components.

BUT someone that’s using cabling to modify the way something sounds... NO!

Very right....

Not because cables are all alike but because they cannot beat control of vibration neither compete with the decreasing of the electrical noise floor, and beat acoustic passive treatment and compare to active acoustic control...

CAbles change are SMALL compared to all that...

I dont understand fixation with cables, those who negate that they are different which is evident and audible and those who pay a big amount of money vouching that they transform all their system...

The 2 groups war between each other blind to the more important way to improve their system....

Incredible!....

Our friend mechanician is right, the power supply and the electrical grid of the house are way more impactful....  

Ok, so what I've gathered here is that the better a component is, the less it needs a tweak yet the more it is affected (not necessarily improved) by one.

If you say so. That is not the case whatsoever. But if that is what you got out of it, that is what you got out of it.

It is demonstrably the wrong conclusion. Read the comments on my system page. https://systems.audiogon.com/systems/8367 There’s one where the cable elevators were removed. Actually I think there are two. In both cases the people clearly heard the improvement. Not change, improvement. What it takes a little more effort to understand, this was the same test but in two different systems. The Tekton Moabs in there now are WAY better than the Talon Khorus. Ditto the speaker cables. Heck every single little thing improved between those two visits. But the improvement heard by this one tweak, that did not change.

Totally blows your conclusion out of the water.

Also if you read the Townshend Podium review you will find the same huge improvement I got with my Tekton Moab speakers as another one got with much more expensive Wilson, I forget the model but way more expensive. Multiples. Most would say better. So another one blown out. 

I could go on and on. Suffice to say it is trivially easy to take even the most expensive SOTA system and make it sound a whole lot better- UNLESS it has already been systematically and thoroughly tweaked. 

To put it another way, you don't tweak, you are leaving mass sound quality on the table. 

We all can agree that even the best speakers respond to room placement but is it true or not true in (your experiences) that the better your audio components are, the less they respond to various tweaks?

Totally agree to placement (as they are measurable).
And it depended on the "tweaks" you mean, for the second half of the question. EG: snake oil ones or legit measurable ones?

Cheers George