I dunno about RP but I find open book exams a little harder. The
exam was structured in a way that didn't really give you any time
to look through the book.
Plus side is that some people rely on the book too much and
under-prepare for the exam thinking they can find the answer as and
when they want it. It's very difficult to find exactly what you
want in a 1000 page textbook while under pressure.
