We've just come back from the UK and Japan with Lily (she was 13 mths) and the long haul flights were fine. I just fed on takeoff and as they began descent and she usually fell asleep straight away. The night flights were best. TBH, there isn't really much need to go premium economy because you get the bulkhead seats (bassinet) so you have the extra legroom and noone leaning back into you :) We never had to line up in any airports and we took our Milano stroller right up to the gates and they were waiting as we got off the plane. Tokyo (not sure about the rest of Japan) is an amazing place for parents as far as facilities go. I was very impressed!! I reckon it would be easier travelling on a plane with a baby who isn't 'moving' as they can happily lay in the bassinet playing. Lily was always wanting to be up and about and I couldn't really sleep when she did in case she woke up and climbed out of the bed

I would totally recommend AirNZ and their new planes too. They have hanging bassinets which are higher than the old ones and are much more comfy for baby and easier for parents to move around. Plus we found AirNZ more accommodating with giving us a whole row to ourselves