My son is freshman at Cornell majoring in pre-med and I have friends who have children at Duke currently. I am biased to Cornell and admit that Duke is an excellent school. A couple of points, I would check out the World University Rankings and compare Cornell to Duke, in several it is many places below Cornell which is due to the incredible reputation Cornell has internationally as a research institution, it has been around longer and has a better pedigree in the hard sciences. I also question somewhat the selectivity point you make, Cornell is plenty selective but also very different due to its stand alone “Schools” structure, Hotel, Architecture, ILR, ect. which are targeting a very specific applicant and can affect the acceptance rate. I also think Duke has made lowering the acceptance rate a specific goal so wouldn’t get too hung up on that-I know many kids from the South who apply there because its got great sports and is in a relatively warm climate-not great reasons to pick a school. That said my friend’s son is from Houston and very happy at Duke majoring in Poly Sci, but its hard to overlook Cornell’s reputation in the hard sciences.