It's not easy to fit a year abroad into an academic schedule, especially in a STEM field. However, the payoff is fully worth the challenge. Not only is grading and credit transfer from the Freie Universität favorable, but the semester break (only available if you do the full year!) affords you the opportunity of doing an internship abroad. Don't make the same mistake I did by passing up this chance!
I can only assume that Dr. Carmen Mueller is the same model of organizational efficiency and dry humor that she was when I studied in Berlin in 2014-15. BCGS does most of the heavy lifting, administratively, for the study abroad process, leaving you free to study at the three offered universities in Berlin, explore Europe, widen your horizons, push your comfort zone, and all the other things commonly associated with studying abroad (hint: aforementioned cliches lose their luster but they exist for a reason). Also, your German-speaking abilities will be miles better when you come home.