I'm exclusively breastfeeding, and while that is wonderful in so many ways...it leaves Kyle out. We introduced the bottle when we got home from Tahoe...having really no idea how it was going to go. Many of my friends tried a couple different nipples. I pumped 4oz, heated it and down it went, in less than 5 minutes. A mystery about breastfeeding...you have no idea how much your little one is eating. Josie slammed the 4oz and wanted more. We were so proud of our little girl!!!