Why do you think that China has done better than the USSR? China didn't become Maoist until the 50s, so it has had about 60 years of 'communism.' The USSR lasted from 1919 to 1991, so a total of 72 years. Its collapse took only a couple of years, so China's system (which has strongly moved away from the original Maoist system, and is very far from Marxism) could end too without much warning. It takes time, I think, for the generations to change enough for the atrocities before communism came to be forgotten. The original generation in the USSR would have passed memories on to their children, but their grandchildren had had enough. You said you wanted less communism is bad. Personally, I wouldn't like it, but on a broader scale, Marxism was laid out pretty specifically for an industrial economy. Most of the Western world has moved past that system. Proletariats as Marx knew them don't exist on a large scale anymore. I find it amusing that most of the socialists and communists at my school come from a solidly middle-class background. They are the bourgeoisie. If a dictatorship of the proletariat were implemented, they would lose out. That's why I left the red ranks, I couldn't shake the feeling of being a hypocrite.

If you haven't done so yet, The Communist Manifesto is a surprisingly easy read. Engles needs a lot more credit than he gets for his writting style. If you really get into it, Capital is also a mainstay, but is pure Marx and much denser (and longer in general). There are some other shorter works and letters, often printed with the Manifesto that can help you too.