Here's a comparsion for someone lucky enough to have tried both racquets. There were actually two versions of the Tour 90 made: the "original" one for Pete, and the later one used by Federer. The earlier one was heavier, about 365 gms unstrung, and the later ones weighed 340 gms unstrung. The heavier ones are much harder to find...most of them weigh in at 340 gms. The St. Vincent was stiffer and heavier than later versions. I wonder if the hypercarbon and the extra weight in the "original" Tour 90s were designed to match these specs. It seems reasonable that they were designed to play like the St. Vincent, only with a slightly larger face. I am lucky enough to have an "original" Tour 90, but not a St. Vincent. I'd be very interested in a comparsion, if anyone could actually offer one.