You won't find much that is worth reading. The vast majority of what's written is either by electricians trying to help people who know nothing wire a house, or by audiophiles who read the stuff written for people who know nothing about wiring and so now they think they know it all. Almost none of what you will find is written by guys with real hands-on experience actually doing this and listening to the results. That would be me. Most everyone else is clogging up the interwebs repeating what they read somewhere. Or they paid some electrician to do something and so now they are repeating what the electrician told them. On and on.
The reality is in terms of money one 20A wire straight to the outlet is a huge upgrade and hard to beat. But not for any of the reasons you are likely to read about. Also yes every single tiny little thing you do will indeed make things either better or worse. I have put little dabs of contact enhancer on my circuit breakers and the improvement is just as great as if the same dab was used on the speaker terminals. Not conjecture. Did it. Heard it.
I am a very value oriented big picture audiophile. My obsession with awesome sound is about a million times greater than my income. The reality is that for every one thing you do that's one less hour or dollar you could have done somewhere else. In the big picture, bottom line, you said "AV setup". As long as that is the case do yourself a favor, run the one line, and don't waste a single second more on power. You have bigger fish to fry.
The reality is in terms of money one 20A wire straight to the outlet is a huge upgrade and hard to beat. But not for any of the reasons you are likely to read about. Also yes every single tiny little thing you do will indeed make things either better or worse. I have put little dabs of contact enhancer on my circuit breakers and the improvement is just as great as if the same dab was used on the speaker terminals. Not conjecture. Did it. Heard it.
I am a very value oriented big picture audiophile. My obsession with awesome sound is about a million times greater than my income. The reality is that for every one thing you do that's one less hour or dollar you could have done somewhere else. In the big picture, bottom line, you said "AV setup". As long as that is the case do yourself a favor, run the one line, and don't waste a single second more on power. You have bigger fish to fry.