I am in the process of trying to get on over there. I have been working with VOR holdings and was asked to come for an interview next month. They said, one day in MCO, a short sim, a few questions, and pretty much everybody gets hired. And they have 100% pass rate when in China. From doing a little digging, I have found out that this isn't true, at least for Tianjin. When I talked to the nice folks at WasInc, they were more honest. The interview is 8 to 10 days which includes the CAAC written, checkride, and medical. They didn't bad mouth VOR but they did say, well, if they said come to MCO for 1 day, then that would only shorten my time in China for a day. Also, I had bought a ticket to MCO for this, which now I have credit for, but Tianjin will pay for me to come to China for the whole deal. Also, from what I found out talking to WasInc, VOR will give you a 1099 at the end of the year, and the other companies, which are foreign, do not. I'm not saying don't pay taxes, but with the foreign guys, you have some other options in terms of how much you pay and such.
The people at VOR have seemed nice, but that's only been over email. When I've asked for them to call me, they haven't. And, the interview that they set up for September is the thrid one they've set up for me, and then 2 days prior I get an email saying that the Tianjin guy can't make it so we have to reschedule. The folks as WasInc actually called me so I know that they have real people there.
From what I've read, the contracts are the same with each company, but how much support you get while in China, or where ever varies greatly.