I have the avant single electric pump and it works but I only get 3/4 oz. Each pumping session and most of the time I still feel pretty full after pumping. I am wondering if I should by the medela PIS I was originally going to but recieve this one as a gift so I wanted to try it and save the money. Did anyone have one pump work alot better then others. I am 3 weeks pp and I return to work on Tuesday so I need a couple of bottles stored.