Very comfortable, and for satin it breathes like a charm.  They don't get too hot or too cold.  Make sure you get your size correct, as it seems the sizes run a little large.  When I go up a flight of stairs I am constantly pulling up the front of the legs as to not trip on myself.  The sleep mask seems to be the only downside... as it is ho-hum and not comfortable.  The value you get with these is almost unrivaled.