I bought these after giving up on breastfeeding my first week home with my son.  I really like being able to buy the extra parts easily and being able to find the extra parts in the store.  The bottles are super easy to assemble but it's not easy to put them together in a hurry so I usually have to have some made up.  One of my bottles is starting to leak around the nipple area and going from stage 1 to stage 2 nipple is kind of annoying.  Stage 1 doesn't put out very much and stage 2 lets too much come out.  However, as a first time parent I really liked these.