From personal experience (2 years, China), China has some of the negativity but it's spread out far more and is much more centered on working conditions. Generally, from my experience, overall quality of life in regards to openness to foreigners, access to facilities, food, entertainment, expat scene, create a far more positive experience than living in Korea. Working in China, you get paid less or equal depending on how hard you look, but schools are generally a bit more fair and aren't out to make your life a living hell. You also get a choice of where you work, rather than throwing your chances in with EPIK, who can put you in the middle of no where. There are traces of Confucianism in the workplace, but it's much much less than Korea. You can talk straight to most people, and if you don't like it you're free to go without the endless make-you-feel-bad bullshit.
In short,
Expats in China are far happier than the ones in Korea. Much less bitter, more focused on their jobs and careers and generally loving life. From my experience, at least.