But their leadership does change, every decade or so, and the CPC is also the largest political party in the world, with many million's of member's.
Again, I agree with your basic premise, however there are other factors to consider.
1) As Rafi mentioned, the CPC is the biggest political party in the world. And almost everyone in China, has at least one family member in the party, or knows someone in the party. Who wants to turn on their own family members, their friends and their co-workers?
True that. But remember how East Germans used to spy on their own family members? What makes you think that Chinese are any different? Human nature doesnt change, even if the race is different.
Again, I may be wrong, but majority of those members are members out of fear and not loyalty towards the party or its ideology. So if time comes, what makes you think people wont rebel?
2) The CPC has the highest approval rating of any government in the world, according to Pew Global research. Two factors: firstly the economic success, and secondly, the fact that the CPC very intimately understands the nature of a People's revolution, and thus have a good understanding of how to prevent one.
Again true. But one also needs to realize that it is one party and its ideology that guides more than a billion people. Again many are members of this party, but mostly out of fear than outright loyalty.
Also, there is constant pressure on the party thinktanks to deliver. Any mistakes, and people might not be forgiving as one assumes. If the time is ripe then a small mistake, a tiny spark may start a revolution, just like the previous one.
3) Historically, Chinese dynasties have lasted several hundred years. By this trend, the CPC still has a LOT of time left, they've only ruled for 50 years.
Communist parties in Europe lasted for only a few decades. Starting with Romania's outing of Nicolae Ceaușescu and culminating with the collapse of the Soviet Union, that was one big movement against the Communist ideology.
Chinese leaders smarted from all that and adopted capitalism albeit in the communist mold. But then again, the party has to constantly deliver, under immense pressure. If and when it cracks, expect the worse.
Maybe I am biased in favour of the CPC, being a patriotic Chinese person myself, but I still think that they are in a very strong position.
For now, yes. But who knows what may happen in the future. People may get disgruntled looking at the Hong Kong model or the Shanghai model and would ask for such in mainland China. What then?
, Iran 
