I left China in the 90's for the US. Went back in 2004/2012. The change in terms of growth of Christians was astounding. In '04, there has been only a few inroads by missionaries. The local villagers heard of them and thought they were some sort of foreign phenomena. By the time I went back in '12, the 50%+ of the village walked a few kilometers for services every week. My grandmother had to get helped by my 2 aunts so she could walk to church. They had one big bible in the church w/ a traveling pastor who would rotate every day of the week at a different location. Some families have a copy of the Bible...probably through illegal means. Even some of the Communist officials in top tier cities are believers now. I met one CCP guy who was in charge of some health department and he was wearing a cross. It turned out he converted to Catholicism in '09. Most people won't tell you they are Christians though unless you ask. There is a risk about saying that you are one, but most government officials don't care unless you incite revolt. Just don't be stupid about it. The one CCP member said "As long as you do your job and achieve results, they don't care if you believe in Mao, money, or God."

On the other hand, the lack of dogma and guidance for interpretation has led to some apocalyptic cults like Eastern Lightning and others resembling the old Taiping Heavenly Kingdom stuff. The CCP cracks down on those cults just like they do on the Falun Gong.

I think the reason a lot of people are converting is the lack of a moral compass within Chinese society. Confucianism was suppressed for a few decades and often blamed by the Republican and Communist governments for China's Century of Humiliation. There are a lot of corruption, cheating, lying, etc all the moral problems associated with a newly rich society and A LOT of Chinese people are fed up with this type of worldly indulgence. It's NOT unheard of for children to cheat their parents for money, children abandoning their parents, breaking contracts in business, soliciting bribes for favors, etc all of which was condemned in the old Confucian society. As for why Chinese are not going back to Buddhism and Taoism, a lot of it has to do with what people see as ineffective cures to the moral problems. You have to PAY A LOT of money for a Buddhist priest to bury your dead and a lot of them are just as corrupt as the CCP. It's not rare to see a fat monk eating meat and ignoring the poor dude by the edge of the road. There are also some scams associated w/ monks begging for money when they are actually well off due to the CCP support for the monastery. I know not all Buddhists are like this, but Chinese Buddhism is heavily corrupted. It's not "pure" like Tibetan Buddhism or other sects.