Once you step foot in a Chinese airline you will find it VERY difficult to leave. There is an acute shortage of pilots in China. Getting a pilot to join is difficult enough. So they will try by all means to keep you. Going to another Chinese airline is near impossible. There is a HUGE penalty if one hops from one Chinese airline to another within China - more than a million rmb. And if you want to leave China for another foreign airline you will face extreme difficulties. So be forewarned ...