do you mean the electric pumps? i know that in australia (can't really speak for the rest of the world) medela are easier to use.<-- i'm only basing this on feedback. i work in a pharmacy and we sell and hire. medela make manual, mini electric and electric. if you are going to use it a few times a day, mini electric is out. motor burns out if you use it too often. electric is most effective, but expensive, (in australia upwards of $AU2000) plus you need to buy the manual attachment. if you wanted to buy a manual pump, i'd go for avent over medela as it's easier to pump, and has cool petal massage-y things