Little disclaimer, I've interviewed at Case and only visited OSU. In my humble opinion, I would choose Case. Here's why: class size is much smaller, abundant research opportunities, you get your own operatory, plenty of service opportunities, and clinical training is superb (you place sealants as a 1st year). The cons for me were the price and the PBL curriculum. Cleveland has very affordable housing and some great neighborhoods with a lot to do and discover (though it's not as young a city as Columbus). Good luck in your decision making!