I have helped rig many sailplanes, both composite and conventional aluminum
construction. In almost every case the metal wing are lighter then the
composite. (1-35 and HP-18 aluminum wings are lighter then ASW-20, ASW-27,
and LS-6 composite wings.)
It is much easier to build a laminar flow airfoil and complex shaped wing
to fuselage transition using composite construction. These wing have a
better lift to drag ratio. The decrease in drag aerodynamic drag of the
wing and static drag decrease associated with the wing/fuselage transition
allow faster speeds.
Wayne
http://www.soaridaho.com/
"cavelamb himself" wrote in message
news

At these speeds I suspect surface condition is a small part of the
overall drag.
However!
If the new wing were a couple hundred pounds lighter, then you'd
see some inprovement in speed.
It takes power to stay aloft.
The heavier the plane, the more power is required just to stay up.
Lighter is mo' betta!
Richard