HESI can be "customized" as you said, or it the school can use the standardized version. As a faculty member of a large nursing program, I can tell you that most schools use the standardized exams for specialty courses- OB; PEDS; Mental Health. Often the first year med-surg exams are customized based on the way the curriculum is set up. I definitely recommend using the HESI Review book- they are the ones who make the test, so it makes sense to use their product. Too many resources is a huge problem, so stick to one or two, do as many practice questions as you can and always think about what is "safest" for my patient. Good Luck!