I don’t think the were meant to be heavy or light per se, just difficult to handle due to the energies involved. I imagine that it would be like swinging a gyroscope.
Yeah, that’s the Lucas quote, basically it’s not technically heavy but seems as if it is due to the energy. I suppose his justification for making them twirly weightless lightsticks in the PT is the same reason they’re constantly doing backflips - they’re extra superpowered Jedi or something.