This is a great bottle that I received from my baby shower. My daughter has not had any problems with colic or any with spitting up. The only complaint I have is how long it takes to wash all of the parts for each bottle. I prefer the glass bottle ones due to the PCPs in the plastic. The less exposed our baby is to plastic the better for her. The bottles come with special brushes for the vent system. These however are pretty expensive after awhile. I also do not like that when you refill the bottle with formula the bottle leaks from the side. So you have to make sure that the sides are dry before you twist on the top. The bottles come in pairs and are pretty expensive unless you have a few coupons from Babiesrus. The bottles come with a cap which you can put on top of the bottle when you travel so it does not spill. Overall, I love this bottle compared to others I have tried. My favorite.