I think that this is generally a very difficult question to ask, not because of what happened after the Mao and the Communists won the civil war, but rather when in time you use for the comparison to this aftermath.

For 50 years prior to the end of the civil war, China was in a pretty rough period of transition. After the first Sino-Japanese war in 1894-95 and the Boxer Rebellion, the Qing Dynasty was pushed harder into a spiraling downfall. The economy was already wrecked by the failed modernization movement of the late 19th century (largely due to government incompetence and lackluster support from the Manchu nobility). When the revolution of 1912 occurred, the country was pushed farther into economic chaos as the nation split politically into regional powers. Eventually, under Chiang Kai-Shek, the central government unified in 1927 and the new government was able to somewhat stabilize the economy and invest in infrastructure. However, this was a short-lived reprieve. The Japanese had already split the country by taking Manchuria and in 1933, they invaded and began WWII. With 3,000,000 Japanese soldiers in China during the war, coastal China was largely destroyed and the following civil war only added to the damage.

Now, I guess my point in providing all of this background is that even under Mao's repressive policies and failed economic models, China had been in such a tail-spin for several generations by the time he took over. While it could be easy to say that for much of the merchant class, his policies destroyed their livelihoods and upended the economy, the vast, vast majority of Chinese people during this entire period were peasant farmers and they mostly stayed this way. The mechanics of their work, however changed substantially. In the first few years after 1949, collectivization and government control of industry changed the way in which workers and farmers were compensated for their labor.

I guess, I personally find the question hard to answer outright because there was simply too much in the way of external and internal shocks to both pre and post-1949 economic life in China. Maybe someone else here can provide more details on a comparative perspective, but I think it would be hard to say whether or not the average Chinese citizen was better off in 1931, 1936, or 1951.

As a side note, I do know that if you go back far enough, urban living standards during the late-Song Dynasty were roughly equal to early 1990's urban China. (I'll try to find my source for this when I get home).