<p>You are talking about two excellent schools.
Duke has always been ranked higher, but both are first-rate, so unless rankings are of the utmost importance to you, you should be governed by where you feel the most comfortable and by which school offers the particular academics strengths of interest to you.
If you were talking about, for example, Princeton vs. NYU, I think the difference in ranking/academic reputation would compel one to choose Princeton, even though NYU is also a fine school.
As between Duke and Vandy? If you like them equally, I would choose Duke (and to answer Optimistic’s question, there is little doubt that Duke has a more impressive reputation in the northeast for recruiting purposes); but if Vandy appears stronger in the particular areas of interest to you, or if you feel like you belong there more than you do at Duke, then I’d go with Vandy. You need to consider where you, as an individual, will thrive; not where the kid down the street will thrive.
The good news? You really can’t go wrong either way.</p>