Well I haven't heard of that idea before. But it sure looks interesting. As far as I looked into jet streams the speeds are between 100 and 400 kmh so a big sphere could travel with quite a speed. But the acceleration would probably be extremely slow for that giant mass.
And Turtle, that effect is actually Magnus effect. So it would be possible to use that to steer in the wind. Not to mention it would be better to have more than 2 spheres as balloons and whole residential complex as a weight.
As I see it, this particular project would be massive, actually one could compare it to Freedom ship. Vessel that big would move very slow and would only be able to quickly evade something with changing the attitude.
And I would rather fit a fusion reactor onto it. Just in case
Nonetheless, this way we would get a slow and expensive means of transport.
