BAL- i have a medela pump and my oldest was on EMB but we used Avent for him never had any issue he loved them
however we tried Avent, Nuby and finally Tommee Tippee for my daughter and she finally took Tommee (because she was BF she wouldnt take a bottle for months)
my son had horrid colic and we didnt try any other brands so im not sure if it made it better or worse
havent tried my youngest on bottles yet but bought Tommee Tippee for him and kept a few Avents to try