I've done hilly Centuries in the US, Alpine granfondi in Italy and a hilly cyclosportive in France on my Air Friday. The Italians tended to look askance with smirks, probably thinking "this idiot's going to die on his silly bike when he hits the climbs", because the folding bikes they were accustomed to seeing were cheap urban utility bikes… until I passed many of them on climbs and/or descents.