I've ridden tours on 28mm and 32mm in the past and have recently been using 35mm Vittoria Randonneurs. Been slowly graduating to larger sizes. After riding this summer, though, my tires have felt slow, dead and heavy. I have an upcoming tour from CT to DC with significant daily distances so went smaller and lighter on the tires. Load is light, probably 230-240 lbs all in (bike + rider + gear), and pavement the whole way. Will see how they hold up.