Trust me here that I am not defending the Soviet Union in terms of any moral or ultimate economic success (I have ties to a "Former Soviet Republic" and know the failings on both accounts)...but it should be noted that the rate of growth of the Soviet economy, and the rate of improvement of quality of life, outpaced that of Western Europe and the US from time of the revolution to about the late 50's early 60's (give or take).

It should be noted that Russia at the time of the revolution was barely "developed" and was fully in the grips of a system based on serfdom bordering on (if not actually equivalent to) slavery. It was, in common parlance, "backwards". They were coming from quite the depths, and made great strides.

In doing so, they brought their standard of living up, and their level of "development" up, while managing to bring their agricultural production down. Sooner or later it was all a diminishing return, but the Soviet system in the early years was at least defensible on certain grounds.

Ultimately that system did not succeed, but it points the notion that different systems might be better for different things. What might have happened had the Soviets edged towards capitalism more in the manner of recent China, or if they had not bankrupted themselves on military spending? (and by extension, what can we as capitalists learn from that last point?)