If any of the jurors had stood up at the beginning of deliberations and said “He’s a good man, and nothing you say will make me vote guilty”, the deliberations would have been short. The length indicates that there’s actually some sober, reasoned deliberation happening — which would not be good for Gosnell.
There are a lot of charges, and discussing them one by one can take time. They have multiple murders and have to decide on the level of guilt for each one if they are being responsible.