If you want a pet theory there is also one that says 23 ga. is perfect, based upon some demonstration using Maxwell's equations. IME solid core wire sounds best for chassis wiring and it's far easier to do assembly with. As to size, one of the best cables I ever made used two different kinds and sizes of wire for signal hot and cold. I think you just have to smoke it and see for yourself.
Allen did indeed like his little SMA connectors and skinny wire. He also liked a bit different sound than I did, so I don't know if the technique will suit everyone's taste.