Probably "a lot" but bike weight is pretty irrelevant to me.
"the old 27.2 eeSilk weighed 295 grams and the new one tips the scales at 345g. The 27.2mm carbon version is 350mm long and weighs 295g. The 31.6mm aluminum and carbon options are 350 and 305 grams, respectively."
I really like my Cobble Gobbler, how much heavier is that CC?