As other people have said, the advantage is speed.
Of course nobody is expecting this tech to replace silicon based chips anytime soon. There's obviously a lot of R&D to be done and, let's face it, nothing may EVER come of it. That's just how science is. We don't know in advance what theories and tech will pan out.
As for leakage between structures? I'm willing to bet we don't need perfect isolation. Just enough isolation that the interference is predictable. (Much like electrons in silicon...)