Instruct: Classify a review as either positive or negative.
Query: Poor quality control: milk seeps from bottle seams

Love the idea, and it works great... except that the bottles are very poor quality. I've had to throw half the bottles away already, due to several of them developing slow leaks from their bottom seams. Can't recommend purchasing this unless the manufacturer can source a better-quality bottle.Has anyone tried substituting with Ameda or Medela milk-storage bottles? Do they roll down the slope correctly?