This article compares and evaluates performance of two main current socialist economic-social models. One is Cuba’s central plan characterized by state large enterprises predominant over the market and private property, with mild market-oriented structural reforms that are ineffective in generating sustainable socioeconomic development. The other model is the successful Sino-Vietnamese “socialist market,” typified by small, medium, and some large private enterprises and the market, all predominant under a decentralized plan (a guideline rather than a central plan). In this the state regulates the economy and controls the largest enterprises. The article identifies the characteristics of the three countries, addresses potential barriers to comparison, and summarizes a history of the reforms and their five key economic policies in the three countries. It also assesses performance based on a selection of the twenty most relevant and comparable indicators, elaborates a composite average to rank the three countries, and discusses potential methodological issues. The conclusions summarize the results of the comparison, recommend reforms for Cuba based on successful Sino-Vietnamese policies, and outline the research agenda for the future. The article is an important contribution to the fields of comparative economics systems, socioeconomic development, methodology, and Latin American studies.