I was given this breast pump as a shower present and it has been a lifesaver! I have the backpack-style which is extremely portable. My daughter arrived a month early and was not able to latch well, so I ended up pumping exclusively for her for almost 7 months! I was able to use the Pump In Style Advanced in the car, at home, and out running errands. There is a car adaptor as well as a battery pack which allowed me to have the power to pump wherever I was. Medela accessories are readily available, meaning that I never had a problem getting items that I needed. I purchased a breastfeeding cover and that allowed me the privacy to pump in the car even on a busy road.
In terms of effectiveness, I initially rented a hospital-grade pump to use but found my PISA even more effective than that one! LOVE my pump in style :)