China Airlines is fine. Service is great and seat is OK. At least 50 inches of pitch and a old "cradle" style seat in biz. Its good enough for sleeping.

Air China or any other mainland carrier sucks...avoid at all costs. Your business class experience will be close to EVA economy deluxe seating and service standards...all with that world-famous mainland Chinese service .

I would avoid Air China until you can be sure their entire fleet has been retrofitted with the new seats. As of now I doubt that even one plane has so forget it, don't even think about it, avoid at all costs, ect, ect!!