My 2 cents and slightly biased as my D20 will be at Duke in the fall.
- overall, the Duke student body will have higher test scores and GPAs
- Forbes ranks Duke #8 in the U.S. and QS ranks them #25 in the world. USC is #30 and #129, respectively
- Duke has always been a Top 10 university; USC is a relative newcomer and wasn't even in the Top 50 until the mid-1990's. To their credit they have come a long way from the days of "University of Spoiled Children".
- Duke has a much smaller student body: 7,000 undergrads (16,000 total); USC is much larger at 20,000 undergrads (48,000 total). With such a small campus footprint, one does feel packed in like sardines.
- Duke's Student/Faculty ratio is 6/1; USC's 9/1
- Duke endowment: $8.5 billion; USC $5.5 billion. Duke has 50% more endowment money than USC that's $275,000 per undergrad versus Duke's $1,200,000 per undergrad.
- Duke sits on 8,000 lush acres; USC sits on 226 concrete acres. Heck the Duke Gardens (55 acres) are almost 25% of the total size of USC's campus!
- Duke campus is absolutely gorgeous and cries out world-class institution of higher learning.
- Duke feels much like an ivy league college but with great school spirit and D1 sports (Duke basketball, need I say more...)
- Durham NC is an average, suburban southern town within the Research Triangle; USC is very urban and sits in South Central L.A. which is very, very close to one of the worst areas of the city. There is a reason the college gives free Uber rides to students after dark.
- Duke is well known for their Economics, Public Policy, Biology and Bio Medical Engineering programs. USC is well known for their Performing Arts, Business, Engineering and Journalism programs.
- USC has a very large and supportive alumni group but Duke's is also very strong.
In summary, these are two great universities but it all comes down to “fit” and what type of college experience you want. USC is going to be much more like a large public university (e.g. UCLA) than it is a Princeton or a Yale. No wrong choice here.