I used my City Select from birth with dd. I had a liner in it that I used to use but nothing else. When the back of the seat is fully lowered it's quite nice in there, kinda cocoon like. She never had a problem sleeping in there. I never used a bassinette attachment so can't really comment on those but not sure how much use you'd get out of it for the money it costs?

Also, I bought the capsule attachment but have never used it.