So, what are the pros/cons of touring with: 700c tires of, say, 28mm to 38mm size, both same on front or back OR smaller up front (pushing less weight over long distances and maybe better directivity?) with larger (softer, easier on tush, maybe last longer (more rubber in tire), squarer patch on ground making it less liable to skid?, able to handle more weight) in the rear with, say, two sizes between them? With the latter, with two sizes between them, the rear can be pumped to normal max and the front to the same pressure which would be under pressure for a narrower tire and a bit softer for ride/control (more grippy?).