Princeton, Harvard, Columbia for Physics/Math

<p>DS has a choice between the three. We would very much appreciate any input, regarding</p>

<p>a. The rigor of the programs and how well they prepare an undergraduate for grad work.
b. Accessibility and supportiveness of the faculty
c. How aggressive does one have to be to seek out research experiences (S wants to go on to a PhD), or are they readily available? </p>

<p>I have also cross posted this in the Harvard forum and the Science Majors forum.
Thanks for your replies!</p>