I took PE Electric - Power.
The morning went really well, possibly over 35/40. The afternoon was a different animal I'm guessing i probaly got somewhere in the 70% range. Had to really work at a lot of the "knowledge" questions (ones requiring no calculations, just relationships between things). I felt the calculation questions were written in more heavy test speak where you had to really sort out what they were trying to ask you. But by the end I had worked over most problems a few times so I felt better than I did for the first two. Generally felt like I spent the afternoon with a fog hanging around my head.
I do feel like all the time I spent prepping to find things quickly in the NEC & NESC paid off. The Complex Imag. code drill book was useful as well as the sample exams for that. Left me a lot of time to work out the longer calculation questions. My illumination references were insufficent though.
I took the Wildi machines book in mostly because everyone here seems to love it. It paid off, got at least two questions only because I had that book.
If I end up needing to take it again I'll bring an engineering dictionary with me and add some sections to my binder with high-level relationship references to help with those knowledge questions.