The cushioning feels great.  These kept their shape after washing and the thick insulation feels excellent, especially at night.  The Large were unexpectedly very snug to put on (for my size 12), but some people could also view that as a plus, since they don't slip or move much.  As others recommend, I would order a size up.  The package reads:  80% wool, 19% nylon, 1% spandex.