PS on the A350 is D1 level food with a comfortable, but narrow seat. The center armrest is about half the width of a domestic F armrest, so that makes up a little for the narrow seats.
Expect domestic "F" level recline. It's nowhere near a lie-flat. The footrest is pretty useless if you are taller than 5'10".
The air quality and ride of the A350 is an obvious advantage over the 767, though.