Well, you are arguing over semantics. Conventionally, china is a communist country because that's what it claims to be and it had it's communist revolution etc.
I believe what mdma and his friend are arguing is that compared to the conventional view of what communism is, where the state effectively owns and runs everything, china is rather different. Like capatlist countries it has free trade and individial people / buisnesses can prosper. Indeed, they are doing. Expect to be eclipsed by chinas economy in the not too distant future.