"seat stay bridge resulting in a stiffer back end" sounds like bollocks
It's probably true, but also likely that the same mass of metal applied as greater wall thickness on the chainstays would have been more effective, especially if they had also saved material on the seatstays by joining them to the seat tube/top tube junction, and reused the surplus to further reinforce the chainstays.
It's probably true, but also likely that the same mass of metal applied as greater wall thickness on the chainstays would have been more effective, especially if they had also saved material on the seatstays by joining them to the seat tube/top tube junction, and reused the surplus to further reinforce the chainstays.