No political system can make China better.

China's problem is not on its political system. Whether a one party of multiparty system cannot make China better. A western style multiple party sytem may make China worst. You can imagine that multiparty's representatives in the congress may fight hand to hand whenever a topic is in stalemale condition. Taiwan is a good example. It only reduce the effectiveness of policy enforcement.
Furthermore, in the multiparty system, the rich with the help of their money, can bribe lawyers, judges, administrative officials, and police under the name of "Democracy or Freedom", and ordinary people may sell their voting rights to whoever give them money. Government Officials may all be tempted by social rogues, merchants and money tycoons.

People may want to take HongKong and Singapore for examples. But I have to remind them that HongKong and singapore are only a peanut size islands. Their existance cannot be the examples of the 1.3 billion people's China.

The most serious problem facing China today is the quality of its 1.3 billion people. They need to be improved in education overall. So, if we have no way to demand China to reach a state of some advanced western countries,China may have to take 20 or 30 more years to strike over the threshold of advancement.