I have used Dr. Brown's plastic bottles for a few months with my son. I will admit they were expensive, but they were needed for that period of time. The down fall of the bottles is that there are so many pieces to the bottles. I actually ended up losing a lot of the pieces and of the set I may have 2 complete bottles left. With all of the pieces it was a lot to wash and sterilize. Mixing in the bottles was hard! You have to put this plain lid on to combine the formula. Then you have to put the pieces on and then the nipple and then seal piece. Then finally you have to make sure you have it sealed right. The plus side to those lids? Well the plus side is you can store some formula! Which is great for middle of the night feedings grab and go! Now the huge downfall that I had with these is when I lost any pieces I would have to go out and buy a whole new bottle. They did not sell the insides separately.