I also find I pump more when I am not thinking about pumping. The iPod is a good idea. I also had to go back to renting a Symphony. The PISA wasnt getting enough, fast enough. But then I use the PISA in the car. I found when I added a pumping session it would take up to 2 weeks for my body to respond and produce well.
I agree that pumping as much as you can and nursing at home is a great option. It is not all or nothing. You're doing a great job!!