Although Yale has a good law school, Yale itself can feel more like a retirement community for geniuses than a stimulating university: The great Yale faculty members get tenure there decades after doing their brilliant work elsewhere.
Boston University has worked hard to collect documentation of 20th century authors; for my personal tastes, I prefer Yale's collection of documentation of 18th century authors, and Harvard's of 19th century ones.
It's interesting how Penn thinks it has a rivalry with Princeton; this unrequited rivalry reminds me not only of Yale's perceived rivalry with Harvard, but of France's with the United States.