How is iMessage/FaceTime/iCloud service in China?

A non-tech savvy friend is going to China. I need to stay in contact with him while he's there. I've set up WeChat to ensure we're not stalled by firewalls, but I'd really like to use iMessage and FaceTime there. How do iMessage and FaceTime work in China? What about iCloud File Sharing?

Although China is notorious for restricting various internet services, iMessage, FaceTime, and iCloud are not among them.

Your friend would have no trouble using these services, as long as he's either connected to Wi-Fi or has a cellular connection.

I was in Shanghai recently (1/1/17). iMessage worked with no problems. I did not try FaceTime.