Solid core OFC vs stranded OCC copper

I'm same as spatialking. using stranded for internal can be issue with extremely small gauge wiring, frying individual strands when soldering. As for SQ, no overarching reason for one over the other IME.

Well, if we're discussing sound qualities, a little this, a little that, I use combos of everything and various metals as well. I'd say vast majority of what I have in entire system is litz.

I agree with so many variables coming into play hard to determine litz vs solid core alone. I simply tune by ear, metallurgy and cable design all come into play. I've found perfect DIY Helix Image power cable recipe to be combo of solid core VHAudio Airlock on hot, Take Five cryo'd litz for neutral, solid core ground. I've tried all solid core, prefer the litz on neutral. As stated above, plating bring another variable to table, I have tin, silver and gold plating on various cables. And then we have  gauge of wire, connectors ,type of cable, so many variables! The idea of one type cable for my entire system hasn't been something I've contemplated or wanted to try.