I will offer a dissenting opinion. I ride the GAP often, I live just a few miles from it. I have also ridden the entire GAP and C&O. For all the negative thoughts on hte C&O, I will say I enjoy it much more than the GAP. It was just more interesting to ride. The GAP is endlessly the same. Once you hit the C&O it just seems more varied, more to scenic to me. The surface didn't bother me at all, and I rode during torrential downpours. Full coverage fenders are your friends.