picked one up today and tried it out...seems like it hardly sucks compared to my electric pump! it didn't feel bad at all but i was only able to get a few drops out after 3 minutes or so...and DD started crying and it turned out she was hungry so i just nursed her.
is there something i'm missing? it only just barely sucks in my nipple. i'm not sure if that's right being that when i use the electric pump it sucks up a whole bunch of areola as well.
Re: avent isis manual pump
Ditto pp, you need to make sure everything is attached correctly. When I first started using mine I sometimes had to take it apart and reassemble to get it going. Also, you sometimes need to play around with the position of your breast. Sometimes if I'm too full my breast doesn't fit in it right and is pressing against the plastic and I have to play around with it to get the right fit. It definitely takes some getting used to but works great once you do.
Ditto what everyone else said about everything being put together right. I have an Isis as well, and I have found that if I moisten the silicone bits with water before I put them together, it helps them form a better seal. Double check the edges of the insert; that's where I most often find a bad seal.
Even at its best, I don't find it to be as efficient as my PY---I have to pump twice as long for the same amount of milk. It is, however, by FAR the best manual pump I have used.