I would always choose JAL over CX if possible.

JAL has much better food, for one. It looks and tastes much better,
and I do mean "much". They also offer a much more extensive
snacks menu.

Better service as well.

The seat may be the deciding factor for you.

The JAL new "suite" seat in business class is much better
than anything CX offers in the same class. However, the slanted
J seat on JAL on some of their 787s is not good - have
tried it short-haul from TPE. Not comfortable.