Then do you offer the USSR as a positive example of
socialism, ie, desirable economic system & society
relative to the best examples of capitalism?
I would say that they are an example of a socialist government which improved the conditions from what they had before. That's a positive, but I never said anything about it being "relative to the best examples of capitalism."
Under Tsarist capitalism, Russia was a backward, agrarian, and isolated state. Socialism made them into a superpower.
In some ways, they grew even more powerful than America, with more tanks, more planes, more missiles. They were no longer backward; they reached technological and industrial parity with the West.
It may not have been consumer-driven or as focused on luxury as the West, but it was certainly a functional system. It wasn't perfect, and in later years, I think they genuinely tried to improve some of the flaws. Gorbachev was more reform-minded.