Can you tell us what specific office, role, and practice you'd be interning at in each?
That said, I highly advise that you network and talk to people in those offices a bit more to make a more informed decision. For an internship, what matters the most is that you're in an office that matches you culturally, provides you mentorship and support, and has you doing work that interests you. Figure out which of these two most optimizes the above. Good luck!