On local bike path most of the tourists I see are riding drop-bars w/moderate handlebar height. More upright position could be a bit easier on hands/arms/shoulders but then more weight on the butt. Plus leaning forward helps the core do some of the pedaling work. Riding upright bikes I instinctively lean forward when pedaling harder but it's not comfy for arms to be folded up. Even with no wind & moderate 20 kph pace I think an upright position is going to cause significant aero drag. Drop/aero bar combo works great: aero bars not only give a little speed boost but give shoulders/arms a nice rest.