Well, I may be the wrong person to ask: I didn't even apply to Stony Brook, and my thoughts on Columbia are summed up in my signature. ;-)
I knew that the small-town Long Island atmosphere of Stony Brook wasn't for me, and that being part of such a small class would only make it harder. (My class of 70-odd students sometimes feels claustrophobic!) If I weren't such a city person, Stony Brook's great value for low tuition might very well have tipped the balance.