I believe that. I heard a distinct difference moving up from 16 to 12 gauge. I would probably tend to buy 12 gauge high-purity copper before springing for 16 gauge silver-plated though.

I've experimented with quite a bit of wire over the years, although nothing too pricey. I find solid wires not to my liking. Possibly more accurate and just too revealing of weaknesses in my system / room acoustics. I've found the Monster Cable style braiding in most 12 gauge cables being sold clouds things up a bit to my ear. I found some finely stranded 12 gauge cables without the braiding and I've been satisfied with them for awhile now...