The flip side of take-home exams was that they could be really long. Exams were generally four hours apiece, but some of mine were eight hours long. And you needed all the time they gave you! (At least I did anyway....)
I looked it up a while back and apparently the new SAT is only 4-5 hours long, which really put it in perspective for me how nuts[0] Caltech final exams are (especially when a typical finals week for me has several at once) :-P
[0] I mean this humorously, not insultingly—I also don't regret choosing Caltech in the slightest.
Students are expected to follow the exam instructions on the honor system.
It's a refreshing change of pace to take exams when and where it's convenient.