"I'm not saying solid core is better than stranded, I don't know. Just wondering."
You are wondering, me too. I find some identical solid core copper wires as MableShade.com at my work and I will give it a try and compare them with my DIY stranded wire when a dozen of IEC and male plugs arrive here sometimes next week.
One thing that I have noticed from DIY with stranded wires, though they are all same 14 awg, ones with 3 conductors that already well packed in a rubber hose from manufacture(OD: half inch) sound tighter and warmer than those single (individual) ones. Regardless how I braided them or leave them as is, they still sound more open and airy than the packed in rubber hose ones. However, ones that are braided have less noise than non-braided wires.