The advantage(?) of take-home exams à la Caltech is that they can be open everything and 3–5 hours long :-P (For what it's worth, being able to listen to music during an exam, ctrl+F a digital textbook, etc. was super awesome; it would deeply sadden me if that becomes infeasible in the future once enough students stop caring about the Honor Code....)

I had in-class exams at MIT that were up to 3 hours long. Take home would definitely have been nicer.