I will go with EVA Air and just make sure that you book on one of those 77Ws flights, so you get the reverse herringbone seats.
EVA Air is basically an "upgraded" business class with a "Book the Cook" and pre-reserved main course services on both segments.
Amenities are much better with pajama and a nice amenity kit.
I will argue that even the meals on the BKK-TPE flights are much better than CX's meal service on the BKK-HKG flights!
The only thing that CX has but not Eva Air is that there is no "mid-flight snack" service from Taipei to West Coast flight, but there will be a hot mid-flight snack on the return segment.
Carfield