In terms of abolition of exploitation, availability of social welfare, and equity, the Soviet system (post NEP) was superior. In terms of integration with the global economic system as it stands and rapidity of development, the Chinese system (SWCC era) is superior. But the material conditions of these countries and the historical epoch they existed in dictated both of these structures, and I believe they are both well suited socialist economies to those conditions. You must remember the USSR’s own similar period of economic development during the NEP before making comparisons like this