Getting to School: Medela

Medela Freestyle or PIS

First time Mom looking for recommendation on whether to purchase a Medela Freestyle pump or a Pump in Style? I like that the Freestyle allows you to walk around etc. but wondering if that really works?? I am using a rented Symphony hospital grade now and it works great. Want to make sure whatever I purchase will work just as well. I do hate having to be locked down to one spot to pump so many times a day. I also travel for work so that is important too in my decision. Looking for recommendations (good & bad) on these. Thanks!