<p>To try to answer the OP:</p>
<p>First, people have a tendency to obsess about and to overvalue the differences. The three colleges have enormous similarities, starting with virtually indistinguishable student bodies and arts-and-sciences faculties. They are probably about 90% the same, and 10% different.</p>
<p>Academic differences: </p>
<p>Penn’s CAS is roughly equivalent to Columbia College and to all of Brown. But Penn also has SEAS (Engineering), Wharton (Business), and Nursing, which together represent about a third of its students, with Wharton alone being a quarter of the students. That means that a much higher number of students at Penn is engaged in more professionally-oriented education, something that doesn’t exist at all at Brown, and is limited to engineering and is much smaller in numbers at Columbia. Really, the “flavor” that Wharton gives Penn as a whole is a big part of any difference among them. (And obviously if you want to go to Wharton, i.e., follow a professional business curriculum as an undergraduate, then there’s a huge difference between Penn and the others: Penn has what you want, and they don’t.)</p>
<p>Second, as others note, Columbia College has a big fat Core Curriculum that takes up about a third of all your college courses, and more like 80% your first three semesters. That’s great if you want a communal experience with all your classmates and the other undergraduates, and a common general education, and it’s awful if you don’t want that. Brown is the diametric opposite – no general education requirements at all (although of course the vast majority of students there choose courses that would satisfy the distributional requirements of a place like Penn). And Penn CAS is in between, although actually much closer to Brown than people generally acknowledge.</p>
<p>What this means is that Penn is guaranteed to have more professionally-oriented students than the others, and Columbia is guaranteed to have more students who value a common core than the others, and Brown is guaranteed to have more students attracted to a system that respects their choice of what to study and doesn’t force them to check off lists. But an individual student who values a broad base of traditional liberal arts education could be perfectly happy at any of them, and indeed can probably duplicate the Columbia Core at Penn CAS or Brown if he wants (but not the experience of having everyone take it at the same time).</p>
<p>Third: Penn and Columbia both have major graduate-level professional schools: law, business, medicine, engineering, architecture, education, government, etc. Brown has medicine, but that’s it, and I think the medical research community around Brown is much smaller than you would find in Philadelphia or NYC. Anyway, those parts of the university create a certain amount of excitement and activity that definitely affects undergraduates. Professors from those schools teach undergraduate courses (or undergraduates take courses there), people come through to lecture, grad students TA undergraduate courses, you meet students at parties, etc. The flipside is that a place like Brown is much more focused on its undergraduate mission than Penn or Columbia are. Brown’s college probably represents 90% of the job of Brown’s President and Provost. At Penn or Columbia, it’s maybe 25%. Maybe. Columbia, I believe, has somewhat bigger PhD programs than Penn, which are somewhat bigger than Brown.</p>
<p>This is really equivalent to the Princeton vs. Harvard discussions. Brown, like Princeton, is very undergraduate-oriented. Penn and Columbia are more like Harvard. They may have a few more famous professors, but it’s harder to spend quality time with them. (Not impossible, just harder.) Brown tends not to show up that well in the international university rankings, which are mainly just tracking faculty prestige, while Penn and Columbia do fine. But over the past 30 years, at least until very recently, Brown has been meaningfully more popular among high-performing high school students, in large part because it was thought to provide a better undergraduate experience (and to some extent based on neighborhood, I think).</p>
<p>Nonacademic:</p>
<p>Manhattan is exponentially more exciting than Philadelphia, which is exponentially more exciting than Providence. And substitute “expensive” for “exciting” – that’s true, too. People report that Columbia can get lonely if you don’t have money to party with the other kids, and there’s comparatively little campus life because the city is RIGHT THERE. It’s RIGHT THERE in Providence, too, but that hardly means anything. Penn has a little more separation, so it still has vibrant on-campus life, too. Also, Philly is much more student-friendly than NYC – they’re economically important here, but there no one really gives a crap.</p>
<p>All of them have neighbors. Columbia has Barnard, which is really indistinguishable and mainly means that there are more women than men. (There are joint programs with Juilliard, but it’s pretty far away.) Brown has RISD, which means that there are more kids with funny-colored hair and interesting piercings around. Penn has Drexel (more engineering/business/pre-professional types) on one side and what used to be the Pharmacy School on the other, with the Curtis conservatory a few blocks away. It’s really a huge mass of students in one area. Penn also has the University City Science Center, and three hospitals it owns within blocks of campus, so there is an awful lot of medical research you can walk to; at Columbia, you have to get on the subway.</p>
<p>At Penn, if you want to go to NYC, it takes two hours and $10 each way. From Brown, you can get to Boston for $10 and one hour. At Columbia, you can get to where the action is on the subway.</p>
<p>Brown has a mall you can walk to. Penn has great stores and restaurants on campus. Columbia . . . thinks those things are pretty pitiful.</p>
<p>Penn: Off-campus housing is cheap and plentiful, and everyone winds up living off campus (within 0-5 blocks from campus). Brown: I’m not so sure. I think the housing is generally thought to be crappy, and people do wind up living off-campus, but not to the extent they do at Penn. Columbia: Unless you are Julia Stiles you can’t afford to live off campus. Everyone is stuck there.</p>
<p>Columbia’s campus is very compact and defined. It’s elevated, too, so that your ground level is everyone else’s third story – really, it’s totally obnoxious if you think about it. The campus is designed to be easy to police, and to keep the riff-raff out of, so it looks and feels very safe, if a bit claustrophobic. Penn and Brown are both sprawly and integrated with the surrounding city. In Penn’s case, that means a lot of traffic passing through, and some roughish neighborhoods not so far away. The same is true of Brown, except its neighborhood is much quieter and greener.</p>