I sort of disagree. my croix de fer is way more soft and comfy on rought terrain than an alloy frame, with same sized tyres.
In my experience i had to compensate the rigidity of alloy with bigger tyres or softer pressures. Talking about an NS rag frameset here, a similar level of alloy to camino.
is correct. It was different in the days of 28.6 OD tubes but nowadays "steel is comfy" is marketing guff. Big squishy tyres make all the difference.