Took CX F in July LAX-HKG and HKG-BKK (747). For return took JL BKK-NRT (in J 789 I think) and NRT-LAX in F.
No comparison for me. CX won in every category. I muched preferred the food on CX. The JL service was spectacular however I still preferred CX. For the record, cabin temp was just fine.