Stimulated by recent advances in isolating graphene and similarities to single-wall carbon nanotubes, simulations were performed to assess the effects of static disorder on the conductance of metallic armchair- and zigzag-edge graphene nanostrips. Both strip types were found to have outstanding ballistic transport properties in the presence of a substrate-induced disorder. However, only the zigzag-edge strips retain these properties in the presence of irregular edges, making them better initial synthetic targets for ballistic device applications.