Hi K.
My daughter wore the helmet for about 3 months. She is a twin, baby B, and for some reason the way she was in my belly during pregnancy caused her to be born with tight neck musles, forgot the proper name for that condition. so she had therapy for that for a few weeks until everything was fine. but in meantime she developed a flat spot on her right side. so we were referred to cranial tech in miami (we were living there at the time). the insurance ended covering about 80 per cent of the costs, but it did wonders for my daughter's head shape. actually looks awesome now. you're in luck that you're considering doing it now rather than summer months when it gets really hot and therefore there will be sweat and therefore more cleaning of the helmet, because the thing about the helmet is that it needs to be cleaned pretty frequently (esp. in the beginning until the head gets used to having it). otherwise it causes a rash on the forehead. my daughter wore it for 23 hr out of 24 hrs a day. she wasn't bothered by it at all. you might want to know that because the head keeps growing you will have to go back to the place every so many weeks for adjustment (they shave the isndie of the helmet to fit the head properly).
so please do not worry. it will help her head shape tremendously and it will not be a bother at all.
feel free to ask me any questions you might have.
vlora
EDIT:
I just read irene's response so i wanted to clarify one thing. the flat spot in the head, if not corrected could cause major misproportions with the eyes, cheeks, nose and chin. even at 5 months old, which was when my daughter got fitted for the helmet, you could notice one cheek sticking out compared to the rest of the face. so i totally disagree with the previous post since this is not a matter of headshape but rather of a flat spot in the head.