Jan and listers,
Perhaps it is more accurate when you list the weights of centerpull and cantilever brakes, to include the weight of the mounting posts (without which they could not work)... which is probably way more than 100 grams.
While the Campy's may not be the lightest, there are plenty of on-topic superlight brakes like Galli Sports at a claimed 300g per pair or CLB Olympics at a claimed weight of 200g per pair, or Dia Compe 400 at 222 grams (Sheldon Brown certified real weight). I know, at least, that the Dia Compe's work very well.
I really think it's hard to find any advantages in a centerpull design... which is why it's basically extinct. For racing bikes, in particular, the sidepull is clearly king.
Here is our beloved Sheldon Brown's (I know he was a devotee of centerpulls) list of component weights:
http://www.sheldonbrown.com/
-Harry Schwartzman Long Island City, NYC Glad that the forty year reign of Centerpull brakes is finally over