I will try to put together a few elements to try to find out if @Kitewinder Kiwee could be an advantageous alternative to a conventional wind turbine as both scale up.
To do this, let’s try to know the mass of the blades (which could be similar for the two types of turbines) in relation to the nacelle of a conventional wind turbine which contains the hub as well as the generator and the gear multiplier, plus some other elements.
To put it simply, we will assume that the mass of a rope drive transmission would be similar to that of a simple tether including the electrical cable.
Likewise, we will assume that the mass of the hub (very heavy part) would be equivalent to the mass of the Kiwee hub transmission pulley system.
We can roughly deduce that the aloft mass of the conventional wind turbine will be approximately that of Kiwee plus the nacelle without the hub, or approximately double for large dimensions.
Of course, it remains to be seen whether a giant Kiwee would be feasible and reliable.
Description of an 8 MW reference wind turbine, Cian Desmond et al 2016 J. Phys.: Conf. Ser. 753 092013 (see table 1 for the mass of the elements):
https://iopscience.iop.org/article/10.1088/1742-6596/753/9/092013/pdf
Authors: * 
Georgios Sieros
P.K. Chaviaropoulos
John D Sørensen- Show all 5 authors
Peter Jamieson
Figure 3. Mass as a function of size for nacelle and blades.