Something that has not been mentioned re: BHX and Hainan is that until last year these flights simply wouldn't have been considered let alone flown from BHX as it is only the runway extension that has made direct PEK flights possible from BHX. I'm not saying that the extension means that all airlines will now consider MAN and BHX when looking at new UK regional routes but BHX is now an option that wasn't there before, something that MAN seemingly needs to remember.
For what it's worth I think BHX will see continued seasonal charter growth from China but that MAN will be first to secure year round service as it's traditionally much stronger filling the front end than BHX has been,