I have a Medela PIS Original purchased 4 1/2 yrs ago. I used it regularly several times a day for a year and have recently started using it again for DD2. Problem is, I'm not sure it's working to its full capacity. When I use the power cord to pump, it's slower and doesn't to work as well. I used the batter pack power thing today and it sounded faster and didn't seem to lug as bad. I've just returned to work yesterday, but I'm also not pumping as much milk as I was so not sure if this has anything to do with it or not. I don't know at this point whether to just buy a new pump or what.