Personally, I would choose UPenn, for its program is much smaller than that at Columbia. Although UPenn DS is relatively newer, according what I heard about, it is well-designed.
I took an interview last Friday, and still haven't got any feedback. Did anyone has the same experience?
In addition, as far as I know, some applicants got admitted without taking an interview, I wonder what's the difference between those two kinds of applicants.