We absolutely love the Playtex Drop Ins bottles. We tried Dr. Brown's bottles initially, but our son was constantly spitting up. A friend recommended the Drop Ins as they had worked wonderfully for her son. We are so glad that we listened. The bottles are very easy to use. We always buy the pre-form liners so we just drop a liner in a bottle and we are set. It is very easy to measure the formula that our son received using these bottles as well. When using the pre-form liners, the formula is measured using clearly marked lines on the bottles themselves. Cleaning is also very easy. Because the formula only touches the liner and the nipple, they are the only parts that are of real concern for cleanliness. We wash the bottles in the sink after every use but that is all. We initially up them in the dishwasher, but this caused the bottom of the bottle to become a bit distorted. Since the liners are one use only there is no concern as far as that goes for clean up. Our son literally stopped spitting up as soon as we switched bottles. I definitely recommend them to anyone looking for a bottle for their baby.