I've lived in China off and on for the last 13 years, and my wife is Chinese. She, her family, and her friends all use it, and they constantly try to get me to use it.

I refuse to use any Chinese social media. They wouldn't allow something they couldn't control or monitor, and I don't feel like giving them a direct eye on all my private chats, pictures, finances, etc. At least Facebook gives me the illusion of privacy.