The actual, practical negatives for the average person are that it's still a developing country, so much of, say, rural China isn't as nice and developed as higher tier cities. This is a vanishing problem though as the entire country is rapidly developing. You also would have to learn Mandarin, and immigration is very difficult. The benefit system can also be more complicated due to how it was set up in the past, with many benefits being tied to regions, but this again is something being worked on.

The primary benefit of China is that people there actually look forward to the future because of how rapidly it's improving, and that this has been steady since 1949.