Not the time for a flat bar vs. drop bar debate. A matter of preference anyway. Personally, I can't imagine doing 30 or more miles on a flat bar-- on the road. Trail riding requires so much in the way of body shifting and movement it is hard to get frozen into a position. On the road, more subtle body movements come into play. The drop bar allows more relaxing changes of trunk, shoulder, arm, neck, and hand position. It's that subtle variety that keeps one from being frozen into a static position-- one source of discomfort on a long road ride.