what if the nationalists didn�t lose mainland china?

I'm surprised no one has mentioned a split China yet. I would predict a Communistic North and a Nationalist South.

Beijing vs. Shanghai
Yellow River  vs. Yangtze River
Wheat vs. Rice
Soviet sphere vs. NATO sphere

Yes, the KMT would have been much better for China than the communists.

*actually, the KMT and the Soviets maintained on friendly terms, and Soviets did not officially recognize the PRC until it was evident that the PRC would prevail.  Generalissmo Chiang was actually quite anti-American in person, and only realist politics drove him to embrace pro-US policies.  Washington even plotted to supplant Chiang with General Sun Liren, a West Point graduate who was more pro-American and more controllable than the old man. 

China's turn toward communism was inevitable, and only a matter of time.  Nowdays, we blame the Great Leap Forward and the Cultural Revolution, and indeed, they stymied progress, but if one took out those two from the equation, a socialist/communist regime worked better for China at the time.  China during the 1950s, right after the communist takeover and before Mao's mind became unhinged, was far better, on average, and for the average worker, than China during the 1940s under  KMT rule.

The best route would be communist takeover without the Great Leap Forward and the Cultural Revolution. 

Edited by poirot