This question is like asking which section of a 3rd class railway car is more comfortable. My B777 PEK-BKK was distinguished by no IFE system in J and F&B IMO unfit for human consumption. Although only a 5 hour or so flight, it was poor quality and poor value. I was fortunate enough to be able to fly CX on the return. The PEK Air China lounge is poor as it certainly doesn't measure up to other *A lounges in Asia. Connecting in PEK was an unpleasant experience. No assistance from Air China and the poorly staffed transfer desk had rude personnel. The Chinese immigration officers were polite and made the official aspect of the transfer process fast. Security screening on the other hand was chaos.