After trying out 4 different bottles without sucess, my breastfed baby finally took this one.  She was only 6 weeks at the time and I had to get her used to nursing and bottle feeding.  This bottle has been a life saver because she goes back and forth between breast and bottle without any problem.  My little one is 5 months old now and loves her bottle.  I nurse on the weekends when I'm home and pump and bottle feed during the week when I'm at work.  She loves it!  The only problem is that the only store I've found them at is Babies R Us and they have limited supply so I have a hard time...