I think the difference would be inappreciable. I have used the Monster Navajo and found nothing wrong with it at all. On my fronts and center I replaced the Monster with DIY Canare 4S11 covered with teflex, shrink tubing, banana plugs and spades. The Canare sounds 0% better, but it sure looks cool.
If you don't think you are losing anything, (I would agree) then the larger wire won't help.
Look at it this way, more copper between your amp and speakers won't improve the sound as long as what you have is sufficient. If my 4 gauge jumper cables would improve the sound of my speakers I would use them, but they won't.
As before, just my O