These are the best thing I have found for my babies.  They are great at preventing bubbles and the speed of the stage one nipple is perfect for newborns to a few months.  These are the only bottles that I buy.  They also come in several sizes, which is nice.  The cons are that there are more pieces to clean and lose.  You can buy replacement parts though.  The other problem is that the Stage two nipple does not work as well.  The speed is just wrong.  Also, you can have big accidents if you don't check to make sure that the bottom is screwed on… read full review »