M.R.
Think about what you might need after the office closes! That seems to be when babies and kids do things that would need a doctor's care. Ask your potential pedi how they handle after hours problems, are they on call, do they have someone to handle their off days, do they just refer you to the emergency room or make you wait until the weekend is over, do they take newborns and up to what age? What hospital(s) are they affiliated with-your insurance will work better with you if your doc goes to the same hospital as your insurance wants you to go to.
Do you feel comfortable with the doctor? If you do, more than likely your baby will too. Are they willing to answer questions without making you feel rushed (and or like you are annoying them by asking)? Do they have someone that can help out with those little things that just need a reassuring answer like a nurse practioner or physician's assistant in case the doctor is busy? Who gives the baby their injections? My pedi's never gave the shots...saying that it ruined the rapport between the child and the doctor, prefering to let the nurse "do the dirty work".
One that I work with that I know is good and the patients rave about in that area is Ari Silver-Isenstat. He works out of Franklin Square Hospital and I think has his own office. He has a wonderful bedside manner and the kids love him. (moms do too!!)
Dont be afraid to shop around until you find the one that is the perfect fit for you and your baby. You both have to be comfortable!