These were the third set of bottles I purchased. The first set I received at my shower were Avent bottles which contain BPA. I was unaware of the dangers when I started using them. I moved on to BPA free plastic bottles, but eventually the plastic wore out and the bottles leaked. See my review here.
http://www.epinions.com/review/Gerber_GentleFlow_bottles_nipples/content_441620139652
I moved on to a full set of these glass bottles. I have been using them for 4 months now and they are wonderful. They never leak, and the baby loves them.
Also, they work well with the Evenflo tinted plastic bottles which are also BPA free. I love these bottles too. The tops, rings, and nipples are all the same and can be used interchangeably. I use the glass bottles in the house and the plastic when we are traveling. Also, the plastic is easier for the baby to hold by himself. I still like the glass for storage as I am not sure any plastic is safe for long time storage, etc.
These bottles are also great because they are dishwasher safe and they can also go in our bottle steamer. They stay cold when you take them out of the refrigerator. The bottles come with silicone nipples. Make sure you read the package because they can come with different flows. Make sure you pick the correct flow for you little one.