actually i'm using BOTH sets of books. here's my strategy: first, i do the princeton review reading, make notes and flashcards, and do all the workbook problems. then, i go to the examkrackers chapter that has the same material, and highlight the parts of my princeton review notes and flashcards that are ALSO covered in examkrackers. afterward, i do the examkracker problems.
i figure, with this method, i'll have a solid foundation of all the nit-picky princeton review stuff, with a focus on the most important bits (as ascertained from the EK books). . . hope it works!!