The Star Wars wikia is in agreement with you. Interesting how it describes the blades as being "mass-less" (thus presumably weightless too?), yet in the movies the Jedi and Sith wield it as if they were quite heavy. In fact, Lucas was quite adamant in instructing actors to move as if the sabres were very heavy, with an "Excalibur" like quality. Perhaps the hilts are extremely heavy.