@cakyolFor your main system, go up to 6 AWG then :-)At that thickness, almost all copper wires will have negligible resistance.Seriously, as I said, check the inductance and capacitance of the wire and buy accordingly :-)I
I find my Transparent Ultra cables significantly better in my main system. While I have not tried 6 AWG I feel I can trust the engineers at Transparent to have considered it.