Actually, I agree with the -8 LH pilot in that the pilot/airplane interface (cockpit) has a long way to go. The FMC and ECS systems need fixes desperately. Hopefully, they will come sooner rather than later.
From the company's economic perspective however, the airplane is extremely capable and efficient. A simple archived CFP check reveals that it carries 25-30T more freight than the -400ERF for the same fuel burn. That is approximately 25% more efficient with another few percent still to come from the engines and flight control changes. Granted, the airplane has only 16% more volume, but it is hard to argue with numbers like those.
swh,
I hope your A350 numbers are correct because CX seems to have placed a large bet on them. Based on history though, you'll have to excuse my pessimism. Airbus is well known for OPUD (over promise under deliver).