Gauge affects tone, but so does material too. I prefer to only use pure nickel strings beause of that, I think it has a mch better tone, and actually sounds a little better a few hours in. I personally would stay away from stainless strings because the frets on my guitar are "vintage" meaning smaller, and stainless steel will wear down the nickel frets quicker. I also found when I was forced to use plated strings because Guitar Center had none in stock (they said they recommend them to everyone so they sell out, I would think they should carry more then) the tone was harsh on them.