BMatthews

Yep, it's better all around. At slow speed the extended sheeting will avoid the lip at the covering transition that usually occures between ribs at the critical high point. Because there's no sudden transition the air will stick better and avoid a series of separation bubbles at each spot between the ribs. At high speeds the air will also tend to stay laminar for longer instead of tripping into turbulent flow at those same lips. So it's better all ways.