I know the OP asked about an American working in China. However, I am an American, living in the US, working remotely for a company in China, about 3 years now.

I know the OP asked about an American working in China. However, I am an American, living in the US, working remotely for a company in China, about 3 years now. I thought I might offer a perspective from the opposite way. The only difficulty I have is language. Sometimes I feel like I am being very clear about something and I still can't convey it. So I take a step back and break it down into a list. This helps. The time difference is manageable. Everyone is really friendly. The other interesting thing is that everyone in the China office knows about the Americans working on their team. I get so many e-mails and I even won a prize at our company party. I have a certain reputation it seems for not sugar coating anything. I did have one odd experience. It is common to use the term "Na Ge", pronounced like "Niggaa" in China and and when I first heard it, I thought that they were using the slang word we all should never use. It was weird because the conversation they were having was about a recent crime. I asked later about this because I couldn't shake that it was being used and it turns out the meaning is something like "umm" or "that one" etc.