Just an update, after talking to friends that have done PE + bassinet or sky couch, they all overwhelming prefer the sky couch for a baby/small child as it allows the baby to move versus being stuck in a bassinet.

As a single adult I will probably not opt to fly sky couch to the USA again after having such a poor sleeping experience. It wasn't particularly comfortable, the seat belts dug into my back, the staff seemed very overworked and it was very, very loud with lots of screaming children around me. I realized by flying it that for me personally, a calm atmosphere is important for me if I want to get a good sleep and the packed, loud, stressful economy cabin was the opposite of that.

Plus I felt super guilty having these stressed out parents all trying to survive the flight with very bored children, whereas I had all of this space and we were sitting right next to each other. This is a personal thing but honestly I came pretty close to swapping with them. It felt so rude to have so much space just for me and they had so little!

It might be different on a flight to Asia that is less family orientated and more adult orientated.