Having flown LAX - BKK a few times (in a decent seat on a good carrier), how anyone can state "19 hours, easy-peasy" or "Seriously though - the future is ultra long haul" either has never suffered the ordeal of an ultra long haul experience or must knock themselves out for the duration of the flight if they have.
It is an awful experience and I just cannot begin to imagine what it would be like in Y and I certainly have no intentions of ever finding out.