You are never going to find a completely impartial source. I vetted the one I provided for accuracy and I was impressed with its explanation of the complexities of the current Chinese government.
I also found your original question a little flippant, so that is why I gave such a blunt answer. I was not trying to be obnoxious, but I can see how you would think that.
While I postulated China may have more total prisoners, their population is considerably higher than the US. So proportionally to population level,(per capita) I still think the US would be number one.
I don't speak any languages of China so my ability to research primary sources is greatly limited. Having said that, I am about as impartial as they come and I am good at separating the true bits of propaganda from the falsehoods and exaggerations.
I am sure you see things from your perspective and I see them from mine. I personally look at metrics like policies and their results rather than opinions. For me, the biggest indicator of fascism is the wealth gap. In this respect we can see most of the developed world including China is run by monied interests dominated by an inefficient system of late stage capitalism.
Although I appreciate leftist thought and I have marched with the socialists in the past, I no longer feel they can move the needle. Fanciful thoughts of revolution are just that. The reality is any revolution would likely produce a much worse system than we have now. China is a great study of how capitalism can be somewhat efficient at first, but then quickly perverted into a system that has created the biggest wealth gap in history.
There are many possible solutions or ways forwards and the best are ones that serve all parties to some degree. There will always be winners and losers in policy but the test of good policy is is it palatable to the loser.