AFAIK the closest we got to full blown capitalism was Chile under Pinochet. The "Chicago boys" implemented policy that came close to a totally free market. The results were that the upper class gained wealth at a higher rate than anywhere else. The poor people died of starvation.
Indeed. What would you call the closest full blown communist experiment? Soviet Union? Venezuela? North Korea? Vietnam?
Really hard to answer. I'd say the Soviet Union because they had the political infrastructure for localized government by the workers (Soviets). They never gave them any real power tough and kept it centralized.