Hornet:
It all depends on which airline as to how you are treated. Although some of how you are treated will have to do with your personality as well. There were 12 of us at Far Eastern Air Transport and we were treated very well by the company. Some of the senior pilots were resentful of our presence since we were the first foreigners hired there and we made more money than they did.
Five of our group went to EVA and all regretted that decision since EVA treats their pilots ( especially cruisers ) badly. Within two years they had all been fired or left EVA voluntarily. You would probably hear a different story from guys who went to EVA in the mid 90s as Captain. They were treated very well with good contracts and a lot of respect. Sadly that has changed. Last I heard they will be laying off 60 ex-pats.
I know one guy at China Airlines who has been there for more than 5 years and he likes it. China Airlines seems much better than EVA for ex-pats. Last I heard he was a little worried about his job because of the slowdown.
All in all I enjoyed the Taiwan experience and would go back in a heartbeat if the contract was good. The people in Taiwan are very friendly and genuinely like westerners ( even Americans ).
If you have any info on what China Airlines is doing I would like to hear it.
As for Hainan Airlines having a few ex-pats I had heard that as well, but had never confirmed it. As far as I know that is the only mainland airline that does.
Tim