What's the difference between Fraxel repair 70% ablative and co2 fully ablative?

I have visited two dermatologists regarding laser resurfacing for the face. They both suggested erbium and co2 for the eye area, however one recommended fraxel repair 70% ablative for the rest of the face whereas the other recommended co2 fully ablative. He said that co2 fully ablative has less chance of scarring than fraxel repair 70% ablative. What do you think? Thank you.