I would think that the GT triple triange frame design would make for very, very little weight difference as compared to a more traditional frame design, not much added tubing. Probably much more weight variation possible due to the tubing materials and joinery techniques used. GT road bikes were available built with steel, aluminum, aluminum-scandium and titanium. GT briefly sponsored Lotto and Jelly-Belly pro teams and I recall that they also once sponsored the US-national amature team. Seems to me that GT road bikes never really gained much acceptance for road racing. One of the few road GTs I ever remember encountering "in the wild" was Chan McRae's national team issue GT, probably right around 1992 or 1993.