I've measured the polished and unpolished tools with a caliper, and they don't differ in thickness. The sharp edges seem to give the impression that they are thicker, but they're not.
I do tend to buy the older Soldiers and Pioneer-series knives though, because the sharp-edged, unpolished tools give a noticeably better "bite" on fasteners. That wire stripper you mention works very well for striking ferro rods, BTW.