A few quick specs from Sanyo's website
CP1300SCR - 35g
CP1700SCR - 46g
CP2400SCR - 60g
RC3300HV (NiMH) - 65g
GP 3300s are around the 65g mark too.
So you can see a BIG difference in weight between the basic 1300 mAh NiCd cells and our racing cells - almost twice the weight in fact.