Does anyone have any experience or know anything about the Whittlestone breast pump? Other than through my web search, I had never heard of it. I currently have the PIS and have not had much success with it. Is it possible that my breasts just do not respond to the PIS? Or could they be unresponsive with pumping? I feel like I have tried all the "tricks" to encourage a higher yeild with no positive results. Even if I am away for the day, it not uncommon to get an ounce total out of my breasts per session.