With my second I only used the playtex drop ins. I would pump right into them. Now with my third - I did't want to wash all the extra parts since I connected them to a medela pump... was going to use all medela bottles and nipples. When I've used the wide slow flows with my son he manages to get the nipple stuck down and I have to pull it out or it will pop out on its own. Any bottle suggestions out there besides playtex or any nipples that will work with the medela collars? Thank so much for the tips.