I love them too! They are so easy to clean. I hand wash the nipples and put the bottle in the dishwasher. Although, I will say, for formula feeding, the only thing I have a problem with is that the scoop for the formula is the same size as the top. We us a small funnel to help. Also, a plus is that the bottles attach to my Medela pump. Easy pumping and storage!
I would not buy so many at one time unless you have already tried them... apparently babies like different kinds of bottles and you don't know until you test them...
Re: life factory glass baby bottles
They also transition into toddler sippy cups! You just have to buy the toddler toppers from LifeFactory