I nursed my son and was very nervous about introduing a bottle. I had heard about all these HORRIBLE experiences that women have had... from thier babies not taking a bottle, to having to trying many different bottles and so on... it was very scary. One day my husbad and I were buying a new car and I had the option of nursing in the bathroom (which was gross) or using the bottle that I had pumped for these reasons in the first place. I choose the bottle and my son had no problems at all. He was so happy, I started to pump more and use the Advent bottles more and more. The four ounce bottles are great for little ones. We love advent products I was able to swich from nursing to bottle with out any problems at all!!! Plus now as he's growing they have different sizes of nipples that you can use and these great sippy cup tops that fit onto the bottles....My son is still using them and he's six months old!!!