I don't "need" the PE, but I did need the FE in order to get my P. Eng. (I have a B. Tech. (EE) and gaining licensure is contingent on passing the FE first). When I finally got around to writing the FE in October 2012, it just felt like I had started something and was leaving it unfinished...
I would recommed the complete Complex Imaginary set as it conatains a number of rotating equipment problems aling with some good protection problems as well. I found it quite useful as a reference during the exam.