dClbydalpha so what is the advantage?
Better control of noise footprint.
Less moving parts.
Less maintenance.
Less unfriendly lubricant.
No need for TRDS alignment.
More freedom in tail rotor design compromise.
More options in MGB layout.
I'm sure there are more.
Why keep asking about battery weight? A claim was made earlier about motor weight ... I think people are answering that and that alone.