My daughter was 2 yrs. old when she started riding
rear-facing in the Bouelvard. She had been riding
forward-facing in a seat without any headwings. The headwings on the
BLVD never bothered her because I dramatically/enthusiastically/excitedly "played up" how wonderful they are for sleeping support (plus the fact that she could watch everything longer in the windows as they fade into the distance rather than having them speed by as happens when facing front). When her older siblings were in the back with her, she was even more content. I believe kids will generally reflect back the feelings we show. If you act like you don't like them, kiddo could easily pick up on that. I'm not saying to ignore genuine discomfort, just that it's not as likely to be genuine discomfort unless the child has a sensory issue of some sort.