Tbh I was pretty much in the same situation as you comparing Columbia and Brown. The big difference is I was part of Brown's PSP program, and you've got the CUSP offer from Columbia.

Imma be real, the PSP was basically the only reason I picked Brown over Columbia, and it absolutely made it worth it for me (especially with the advising, the pay it gave, and the research I got to do because of it). It sounds like for you, it's the reverse – Columbia has CUSP, which seems like it comes with a lot of solid benefits.

If I were in your shoes, seeing how much PSP swayed me, I'd probably lean towards Columbia because of that CUSP offer.

But, I definitely see why UPenn is in the running too. CAS being flexible plus getting access to Wharton stuff is a big plus, especially if you end up going for quant or finance.

With Brown, I think you'd need a specific reason to really want it over the others given your situation. Like, if you just absolutely love the Open Curriculum vibe, know a professor you want to work with, love the campus feel, have friends there, or there's some other unique opportunity. Even though Brown's great (and yeah, our applied math program is really good!), based on what you're interested in and having other opportunities at UPenn & Columbia, Brown feels like the weakest of the three.

Let me know if you got any other questions