not how big your rotors are or how many calipers you have
I strongly suspect that most people only have one calliper, although there were some very dodgy twin calliper forks around in the late 90s!
Aside from that, are you actually saying that you can exert the same braking force with a 160mm XC race brake as you can with a 203mm Hope Mono 6 ti?
My S-Works Epic frame (Large 2006) is 2650g
Aye, they got lighter by then, the seat tube/top tube bridge was hollowed out significantly, Brain Lite shock, hollow magnesium mounting, carbon linkage etc etc, the 2003 ones really were heavy, heavier than the Stumpjumpers of the same era.